The time element in the WTO Valuation Agreement and its role as a limit to customs discretion

I. Customs valuation and its historical background. Introduction

The customs procedure for valuing goods is the administrative mechanism by which the customs value of imported goods is determined, that is, the taxable base for calculating customs duties and other import charges (1).

The first formal notion of the customs value of goods was related to the principles contained in Article VII of the GATT 1947; although there was no rule or procedures as such, the guidelines established by that article were definitive for the development of subsequent rules (2). However, these principles were so general that in practice they did not contribute to creating a uniform valuation system at the international level (3).

In this context of insufficient regulations, the first attempts to systematize customs value were developed with the purpose of reducing discrepancies and providing greater predictability to the determination of value.

Indeed, the Customs Valuation Convention established a valuation system known as the Brussels Definition of Value, widely disseminated in Europe, Latin America and other regions, based on a concept of value of a theoretical nature (4).

This agreement responded to the needs of European countries, which had to rebuild their industries, devastated by the Second World War, a process carried out through a strong state presence in the economy, around which the Brussels Definition of Value established a reasonable protective framework. In this context, it can be argued that the Definition served as a bridge between two distinct moments in international trade. (5)

From a chronological perspective, the Havana Charter, which never entered into force, first set out general principles on customs value. Then, the General Agreement on Tariffs and Trade incorporated them into its text in 1947, establishing the basis for subsequent codification. Finally, the Brussels Definition of Value, inspired by these precedents, structured an operational system that was adopted by numerous countries, initially European and, later, from other regions.(6)

Even so, the practice of valuation continued to be heterogeneous, and it became necessary to move towards standards that would promote truly universal application, reducing areas of divergence and disparate administrative decisions.

Within this framework, under the GATT and at the initiative of the United States, the Agreement on Implementation of Article VII of the GATT was drawn up in 1979, which implemented a system based on a positive notion of value, centered on transaction value. (7)

The final text of the Agreement largely reflected the interest of the major economic blocs in standardizing the valuation systems applied in the European Economic Community, the United States, and Japan, while incorporating specific provisions to address the needs of developing countries. (8)

Later, the Uruguay Round of the GATT, conducted between 1986 and 1994, culminated in an agreement reached on December 15, 1993. This outcome allowed ministers from 125 nations to sign the Marrakesh Declaration on April 15, 1994, establishing the World Trade Organization, which began operating on January 1, 1995, in Geneva. From then on, the GATT ceased to exist as an institution, although it continued as an agreement applicable to trade in goods, coexisting with the new treaties approved in the Uruguay Round. Consequently, the previous GATT became known as the GATT 1947, while the new text was identified as the GATT 1994.(10)

The WTO Valuation Agreement adopted in the Uruguay Round contains a text substantially similar to the Valuation Agreement of the Tokyo Round. Therefore, its main novelty consisted of the adaptations necessary to adapt it to the institutional structure of the World Trade Organization, while otherwise maintaining the valuation principles and rules developed in 1979. (11)

II. The Brussels Definition and the time element as a structural element of the normal value

Time, understood as the relevant moment for determining the customs value of goods, is not an essential requirement of the transaction value, unlike what occurred with the normal value in the Brussels Definition of Value. Under that system, the value was linked to the moment when import duties became due, which is why customs could reject the invoice price when significant fluctuations were found between the time of purchase and the time of valuation. (12)

Indeed, within this framework, time emerges as one of the elements comprising the criterion chosen to determine customs value, which, in the case of the Definition, remains unchanged, regardless of the circumstances under which the commercial transaction takes place. This is because the Definition establishes that customs value is the "price estimated... at the time when customs duties become payable." Consequently, the element of time acquires particular relevance, since the price to be set is directly related to the moment when customs duties become payable. Obviously, this moment differs from the moment when the commercial transaction was agreed upon, and the resulting normal price could differ from the agreed price (for example, when purchasing for storage in the country of export) or coincide with it (in sales that meet all requirements and are dispatched within the usual timeframes).

Along the same lines of thought, Rafael Herrera Ydañez (13) explained that, given the freedom that customs legislations had to choose between several relevant dates, (14) “lThe choice must be made once and for all, so that the element of time remains unchanged.” That statement reflects the conception of time as a rigid technical criterion, functional to the internal coherence of the system in force during that period.

III. Article 1 of the WTO Valuation Agreement and the exclusion of the time element. Function and scope of Explanatory Note 1.1. Transaction value as an autonomous method. Structural protection of the transaction value method.

Article 1 of the Agreement makes no mention of time as an essential element for applying the transaction value method. Therefore, it is irrelevant when the sale for export to the country of import took place, or the price fluctuations that occurred in the market between the date of the sale and the time of valuation (15).

However, a review of the Brussels Definition and the treatment it gives to the element of “time” is essential to fully understand the scope of Explanatory Note (16) 1.1 , which specifically addresses this element in relation to Articles 1 (transaction value method), 2 (transaction value method of identical goods) and 3 (transaction value method of similar goods) of the Agreement.

In this respect, Explanatory Note 1.1 (17) was linked to Article 1 because it was necessary to exclude any possibility of introducing the time element as a condition of validity of the transaction value.(18)

This precision stemmed from practices observed in customs experience prior to the Agreement and even in its initial applications, where some administrations assessed the validity of the transaction value based on the temporal proximity between the sale and the import. In such cases, when the sale had taken place earlier, the declared price was questioned, and in the face of subsequent market fluctuations, prices considered more recent were used, introducing a temporal criterion that Article 1 does not authorize.

This precision stemmed from practices observed in customs experience prior to the Agreement and even in its initial applications, where some administrations assessed the validity of the transaction value based on the temporal proximity between the sale and the import. In such cases, when the sale had taken place earlier, the declared price was questioned, and in the face of subsequent market fluctuations, prices considered more recent were used, introducing a temporal criterion that Article 1 does not authorize.

That approach implied a significant deviation, since it altered the structure of the main method, affected the predictability of the system, and reopened margins of discretion that the Agreement sought to reduce by eliminating arbitrary values, in line with its preamble.

From this perspective, the Note aimed to prevent the transfer of comparative criteria from Articles 2 and 3 to the examination of transaction value. It also sought to prevent market fluctuations from influencing the acceptance of the price actually paid or payable, to preserve the autonomy and primacy of the main method, and, converging on this, to prevent the continued use of criteria associated with the Brussels Definition of Value model (19).

With regard to Article 1, Note 1 defines the transaction value and then states that there is no time element that conditions it. On that basis, it clarifies that the price must be accepted even if the sale was completed much earlier, that the value remains valid regardless of subsequent market fluctuations, and that the phrase "when these are sold" does not introduce a time criterion.

In turn, to prevent the logic of Articles 2 and 3 from being unduly projected onto Article 1, the Note clarifies that, although Article 1.2(b) contains temporal references to compare criterion values, this does not alter the general rule that excludes the time element as a condition of the transaction value.

At this point, Lascano explained that the reference values ​​referred to in Article 1.2(b) are called criterion values, and that the rule requires the importer to demonstrate one of the specified points, assuming the burden of proof. He also noted that the mechanism operates at the importer's initiative, without the article authorizing customs to demand the production of such proof, although it does require ensuring the importer the opportunity to offer it (20).

Precision is especially relevant because Article 1.2(b) regulates an exceptional and voluntary mechanism, not a constitutive requirement of the main method. This mechanism uses benchmark values ​​that, by their own comparative logic, require a temporal standard, without authorizing the transfer of that standard to the transaction value without distorting it.

Regarding the functioning of the mechanism, Lascano indicated that the three planned criteria have points of contact, including that the comparable values ​​are in force at the same time or at an approximate time.

Along these lines, point 7 of the Note introduces an important reflection, insofar as it suggests that the temporal pattern of article 1.2(b) should seek consistency with articles 2 and 3 and use the time of export.

This is linked to the fact that the criterion values ​​of article 1.2(b) may come from methods that already operate with specific time references, and that any comparison requires being placed within an equivalent economic context.

In turn, point 8 of the Interpretative Note indicates that when the criterion value comes from exported goods (paragraph i), the reasonable time standard would be the time of export; when it comes from the deductive method (Art. 5 – paragraph ii), the standard would be the sale in the country of import; and when it comes from the reconstructed method (Art. 6 – paragraph iii), the standard would be the time of import.

The foregoing demonstrates that Article 1.2(b) does not create a single normative moment, but rather adapts the temporal pattern according to the type of comparison. Within this framework, paragraphs 6 to 8 of the Note preserve the internal consistency of the system by preventing the temporal reference contained in Article 1.2(b), limited to the criterion values, from being used to introduce a requirement not provided for in the main method.

In this context, the time element operates solely in relation to comparative values, in order to guarantee the economic relevance of the comparison. The transaction value remains outside these considerations, which marks a structural difference with respect to the comparative methods provided for in Articles 2 and 3.

In short, Explanatory Note 1.1 proved essential in preventing operators and administrations from projecting onto Article 1 a temporal element that is not part of the transaction value method. On this conceptual basis, the Note helped to reduce an area of ​​interpretive uncertainty and ensure that Article 1 retains its autonomous character, independent of the temporal context.

IV. The time element in comparative methods of the Valuation Agreement. General introduction

As noted, the element of time plays a crucial role in valuation methods based on comparison, as it conditions the validity of the references used. Indeed, Articles 2 and 3 of the Agreement establish, as a general rule, that the comparison between transactions must be made with respect to the “same moment” or an “approximate moment,” thus constituting an essential requirement to preserve the economic equivalence between the transaction being valued and those that serve as the basis for determining the customs value.

In this sense, the reiteration of this time parameter does not respond to a contingent option, but rather reveals its structural character within the Agreement system, insofar as it is necessary to avoid distortions derived from variations in the conditions of the international market.

From this perspective, time acts as a technical limit that ensures the comparative values ​​used are useful, relevant, and economically representative. Consequently, the time requirement becomes a true condition of legitimacy for using alternative values ​​when the transaction value is not applicable.

V. The methods of articles 2 and 3. Time as a condition of economic comparability

Comparative methods (arts. 2 and 3) necessarily require an external time parameter, which is why time operates as a mandatory requirement to ensure that the comparison is made within an equivalent economic context.

Indeed, the comparison is only valid when there is economic proximity —that is, “same moment” or “approximate moment”—, with time functioning as an external standard intended to guarantee real comparability.

The element of time, under the formula of export at the same time or at approximately the same time, constitutes one of the essential elements common to Articles 2 and 3 of the Agreement. In this framework, the reference point for comparison is linked to the date of export of the goods and not to the date of their sale. The objective pursued by this criterion is to adjust, as much as possible, the economic equivalence between the prices of identical or similar goods and those being valued.(21)

Indeed, the comparison is only valid when there is economic proximity —that is, “same moment” or “approximate moment”—, with time functioning as an external standard intended to guarantee real comparability.

The element of time, under the formula of export at the same time or at approximately the same time, constitutes one of the essential elements common to Articles 2 and 3 of the Agreement. In this framework, the reference point for comparison is linked to the date of export of the goods and not to the date of their sale. The objective pursued by this criterion is to adjust, to the greatest extent possible, the economic equivalence between the prices of identical or similar goods and those being valued. (22)

Paragraphs 9 to 13 of Explanatory Note 1.1 contain the most complete development of the treatment of the time element in the comparative methods provided for in Articles 2 and 3. Unlike Article 1 —where time does not affect the validity of the transaction value—, in comparative methods the time element acquires a structural character and conditions the very legitimacy of the comparison.

In particular, paragraph 9 of the aforementioned Note emphasizes that Article 1 is based on a self-contained, real, and independent price, determined by the sale that triggers the import. In contrast, Articles 2 and 3 depend on values ​​previously determined in accordance with Article 1 (identical or similar goods).

In turn, paragraph 10 establishes that articles 2 and 3 require that the comparative values ​​correspond to goods exported at the same time or at an approximate time, thus configuring an external temporal pattern indispensable to ensure the economic equivalence of the operations compared.

In continuation of the above, paragraph 11 makes it clear that the time parameter is the export and not the sale.

Paragraph 12 then elaborates on the functional definition of the concept of “approximate timing,” which is not equivalent to a fixed interval. Rather, its function is to moderate the rigidity of “same timing.” It should correspond to a period as close as possible to the export date and respect identical economic market conditions and commercial practices.

This implies that time, in Articles 2 and 3, does not operate as a merely chronological datum, but as an economic criterion, such that temporal proximity is evaluated based on market stability and not on rigid timeframes. Consequently, the element of time is essentially case-specific, and its function is to preserve economic equivalence, not to impose an abstract numerology.

Finally, paragraph 13 recalls that the element of time cannot be used to alter the order of precedence between the methods, in particular the priority of the method of article 2 with respect to article 3. Thus, even if a similar good is temporally closer, this does not allow dispensing with the method of identical goods (23).

This precision reinforces the sequential nature of the Agreement and the prohibition of customs discretion in the selection of valuation methods, preserving the internal consistency of the system.

Based on the foregoing, the analysis of the Valuation Agreement reveals that it has not established a predetermined time limit or a rigid chronological parameter that would allow for an abstract and uniform definition of the scope of the "same moment" or "approximate moment" criterion. On the contrary, the system's design itself reveals that the time element does not operate as a fixed magnitude, but rather as a functional standard whose assessment depends on the specific economic and commercial conditions of the case.

VI. The practical determination of the “same moment” and the “approximate moment”. Contributions from national and comparative jurisprudence

The practical delimitation of the time element cannot be derived solely from the text of the Agreement, but requires consideration of the applicable regulations in each State and the developed case law, insofar as these sources, through their specific application, define the scope of the time requirement within the margin of flexibility that the Agreement itself has deliberately left open. This is further explained by the fact that some legal systems (24) establish maximum time limits to define the “approximate moment,” which serve as general reference parameters, but do not exhaust or replace the economic analysis required by the valuation system.

In Argentina, an illustrative example is a ruling by the National Tax Court (25), which expressly addressed the issue of the “approximate moment” in a case involving the rejection of the transaction value and the application, instead, of the method provided for in Article 3 of the Valuation Agreement. In that case, the Court emphasized that the reference to exporting “at the same time or within an approximate period” is neither accidental nor merely stylistic, but rather serves a clear regulatory purpose aimed at avoiding the rigidity that would result from requiring an exact temporal coincidence, which would impose an excessive and unnecessary burden and hinder a practical and equitable application of the method. On that basis, it was held that what is relevant is not “absolute temporal precision,” but rather the existence of a sufficiently recent period that allows for the presumption of stability in commercial practices and market conditions. Following this premise, Explanatory Note 1.1 of the Technical Committee was cited as supporting evidence to justify a functional interpretation of the “approximate moment.” Finally, it was emphasized that it is not enough to measure "days of difference" in the abstract, but that the "approximate moment" must be weighed on a case-by-case basis, taking into account the product involved and the dynamics of the industry itself.

Foreign experience is also particularly illustrative for analyzing case law and its interpretive richness. In this regard, the case that upheld the valuation made by U.S. Customs regarding fresh Mexican asparagus, whose transaction value was rejected, is of special interest. The controversy centered specifically on the interpretation of the expression “at or about the time [of exportation].” Customs maintained that “the same moment” refers to the exact day of export and that, in the case of perishable goods, “approximate time” encompasses a period between one week before and one week after that date, always giving preference to values ​​corresponding to the exact day or, failing that, the closest ones, with particular preference for the lowest value when multiple references exist. The International Trade Court upheld this interpretation, highlighting the reasonableness of the criterion adopted, the technical expertise of Customs and the consistency of the analysis carried out, and concluded, consequently, that the interpretation applied was persuasive and deserved judicial deference.

On another occasion (27), and in a similar context, when debating the applicable method for valuing imports of fresh watermelons, the inapplicability of the transaction value was determined, and the need to analyze subsequent methods was considered. The method relating to the transaction value of identical or similar goods exported to the United States at the same time or at approximately the same time was then examined. In that context, it was indicated that the watermelons in question, being perishable products, were subject to the same criterion previously applied to fresh asparagus.

These examples allow us to draw at least two relevant conclusions that are central to the analysis. On the one hand, there is a clear temporal hierarchy that prioritizes, first, the “exact moment” and, second, the “approximate moment.” On the other hand, the duration of this “approximate moment” is not determined by a rigid mathematical measurement, but rather depends on intrinsic factors—such as the nature of the commodity—and extrinsic factors, such as industry dynamics, seasonality, and price stability. Based on this conceptual framework, the emphasis on proximity to the “approximate moment,” as opposed to simply adhering to a maximum time limit, is grounded in the very economic and normative logic of the valuation system. The Agreement does not conceive of time as a merely formal element, but as a tool designed to preserve economic equivalence between comparable transactions.

From this perspective, a precedent that, even if it falls within the maximum timeframe stipulated by internal regulations, is situated in a different economic context than the transaction being valued, does not satisfy the purpose of the time frame criterion. The mere fact that it falls within a regulatory limit does not, in itself, guarantee that the price used reflects equivalent market conditions, especially in sectors characterized by volatility, seasonality, or abrupt changes in supply and demand.

In this line of thought, prioritizing a precedent solely because it falls within a maximum timeframe transforms a functional criterion into a merely formal parameter, shifting the focus of the analysis from economic equivalence to the arithmetic fulfillment of a deadline. Such an approach is incompatible with the structure of the Agreement, which requires that comparative values ​​be economically relevant and not simply chronologically admissible.

Therefore, when several possible precedents exist within the period permitted by the standard, the one with the closest temporal and economic proximity to the transaction being valued should prevail, even if other precedents are also formally admissible. Proximity to the "approximate moment" is not a secondary criterion, but rather the mechanism through which the requirement of actual comparability is fulfilled.

In light of this principle, using a more distant precedent in time simply because it is within the maximum limit, displacing another that is closer and economically representative, not only distorts the purpose of the time element, but also introduces a margin of discretion incompatible with the regulated and sequential nature of the valuation system.

In short, the maximum time limit set by an internal regulation can act as a legal ceiling, but not as a substitute for the economic analysis required by the Agreement. The valuation is not legitimized by the mere fulfillment of a deadline, but rather by the ability of the selected precedent to reflect, as accurately as possible, the market conditions prevailing at the relevant time of the transaction.

Notwithstanding the foregoing, it should be clarified that the prevalence of proximity to the “approximate moment” does not imply disregarding or relativizing compliance with the other regulatory requirements for the application of each of the valuation methods provided for in the Agreement. On the contrary, the selection of temporally relevant background information presupposes the prior and concurrent verification of all other elements that condition the validity of the applicable method.

In this sense, the requirement of economic equivalence in temporal matters is integrated with the other substantive and formal requirements of the system —such as the identity or similarity of the goods, the commercial level, the quantity, the pertinent adjustments and the respect for the sequential order of the methods—, which must be punctually fulfilled for the valuation to be legally valid.

From this perspective, the emphasis on temporal proximity does not imply undue flexibility in the regime, but rather a harmonious and coherent application of its rules, in which no requirement is substituted or offset by another. The correct determination of customs value thus requires a comprehensive verification of all the normative assumptions of the corresponding method, among which the element of time fulfills a specific, but not exclusive, function.

In short, the interpretation proposed here does not distort the valuation system, but rather reaffirms its technical and sequential nature, ensuring that each of its elements operates within its own scope and in accordance with the economic and legal purpose assigned to them by the Agreement.

On another occasion, the Court of Justice of the Andean Community (28) held that the “approximate time” constitutes an essential normative concept, incorporated into Andean law by the Agreement on the Implementation of Article VII of the GATT of 1994. On this basis, it clarified that this concept does not constitute a fixed timeframe or a merely formal criterion, but rather corresponds to an economic-functional standard, the purpose of which is to allow for real, reasoned, and economically equivalent comparisons. From this perspective, its correct application requires active action on the part of Customs, which must identify comparable transactions carried out within that period, without unduly shifting the burden of proof to the importer. In this vein, the absence of a rigid temporal definition does not allow for arbitrary discretion, but rather mandates a contextual analysis that is reasoned and consistent with current commercial practices. Consequently, it is not legally valid to resort to the last resort method without having previously demonstrated that, within the “approximate time,” comparable goods do not exist or that they do not allow for an adequate valuation. In short, the Court affirmed that the “approximate moment” operates as a legal limit to customs discretion, reinforces the sequential nature of valuation methods and requires a technical, economic and reasoned application of the system, in full accordance with the principles of the WTO Valuation Agreement.

VII. The deductive method of article 5. Normative structure and stepped treatment of the time element

Article 5 of the Agreement on Implementation of Article VII of the GATT 1994 establishes a complex and deliberately staggered timeframe for applying the deductive method. Specifically, Article 5.1(a) stipulates that customs value shall be determined based on “the unit price at which the imported goods or identical or similar imported goods are sold in the importing country, in the same condition as imported, at the time of importation or at approximately the same time.” Article 5.1(b) establishes a clearly subsidiary rule, providing that only when no sales fall under the preceding paragraph may the value be based on subsequent sales, provided that these occur “within a period not exceeding ninety days from the date of importation.”

This regulatory structure confirms that the Agreement distinguishes three distinct timeframes: the exact moment of importation, the approximate moment, and, only in the absence of both, an expressly defined maximum period of ninety days. Consequently, the time limit in subsection (b) does not incorporate or redefine the concept of “approximate moment” in subsection (a), but rather operates as an exceptional and final parameter, intended to avoid the practical impossibility of applying the deductive method.

At this point, the doctrine of González Bianchi (29) is particularly enlightening, who points out that “only the earliest sale in time may be taken into account if it is impossible to find a sale in accordance with Article 5.1(a) of the Agreement. This demonstrates that the temporal distance is not an indifferent fact, but a criterion of subsidiarity that arises directly from the wording of the Agreement, even though the differences between the stages of the time element may be subtle. Along the same lines, the author emphasizes that the analysis of the time element in Article 5 must be articulated with the type of merchandise considered—the same imported merchandise, identical merchandise, or similar merchandise—and with the relevant sales conditions, stressing that the temporal criterion cannot be applied in an isolated or mechanical manner.(30)

Likewise, González Bianchi (31) argues that the interpretative criterion developed from Explanatory Note 1.1 for Articles 2 and 3 can reasonably be applied to Article 5, since the underlying issue is the same: determining a timeframe that preserves the actual comparability of transactions. In support of this assertion, the author cites the Interpretative Note to Article 5, paragraph 10, according to which, for the purposes of Article 5.1(b), the earliest date shall be the date on which the imported goods, or identical or similar imported goods, have been sold in sufficient quantity to determine the unit price. It follows that, in practice, the customs administration may be obliged to approach the maximum limit of ninety days when necessary to obtain a representative sale, without this implying an automatic or unreasonable application.

This same interpretative text also suggests that the determination of the relevant time should be made, as far as possible, through an agreement between Customs and the importer, taking into account the latter's knowledge of probable sales within the period under consideration and allowing for the presentation of additional evidence when this leads to a different and more representative price. This reinforces the idea that the element of time, even in the face of an express maximum limit, retains a functional and dialogical character.

On this premise, it should be noted that the coexistence of both paragraphs precludes interpreting the maximum ninety-day limit stipulated in Article 5.1(b) as an integral part of the concept of “approximate time” referred to in Article 5.1(a). Indeed, both paragraphs serve distinct normative functions within the framework of the deductive method. Paragraph (a) establishes the primary and priority rule, based on the temporal proximity between importation and sale, while paragraph (b) introduces an exceptional safeguard designed to prevent the method from being rendered ineffective when such proximity cannot be verified in practice. If the ninety-day period were considered part of the “approximate time,” paragraph (b) would lose all normative autonomy, since any subsequent sale made within that period would be subsumed under paragraph (a), obscuring the staggered sequence established by the Agreement and rendering the expressly provided subsidiary rule meaningless. From this perspective, the structural distinction between the two clauses is not merely formal, but functional. Article 5.1(a) requires a qualitatively closer temporal proximity, aimed at ensuring that the unit price used reflects market conditions substantially contemporaneous with the importation. Article 5.1(b), on the other hand, allows for a controlled departure from this requirement, but only when the absence of contemporaneous or approximately contemporaneous sales makes it indispensable, and always within a maximum limit expressly established by the Agreement itself.

In summary, a systematic interpretation of Article 5 allows us to affirm that the “approximate time” provided for in subparagraph (a) should be within a shorter period than the ninety days contemplated in subparagraph (b); however, the determination of the specific interval will depend on the circumstances of the case, market conditions, and the economic reasonableness required by the method. The structure of the Agreement imposes coherence and functionality, but at the same time preserves the flexibility necessary to prevent the deductive method from becoming a mechanical scheme devoid of adaptation to commercial reality. (32)

The temporal logic is further relaxed in the case of the method provided for in Article 5.2 of the Agreement, commonly known as the super-deductive method. This provision establishes that, when imported goods are not sold in the same state in which they were imported, the customs value may be determined based on the unit price at which they are sold after processing, with the corresponding deductions. Unlike Article 5.1(b), Article 5.2 does not set an express time limit between importation and subsequent sale. On this point, Lascano emphasizes that, for the application of the super-deductive method, identical or similar goods are not taken into consideration, but rather the imported goods themselves that are the subject of valuation, which may require Customs to suspend the determination of value until the processing and resale take place. González Bianchi agrees that, under this method, there is no strict time limit between the importation and sale of goods, and sales made several months later can be considered, unless national legislation establishes specific limits. Even then, such limits would not prevent Customs from waiting a reasonable amount of time to verify that no sale occurs in the same condition in which the goods were imported, except in cases of obvious circumstances.

VIII. The last resort method (Article 7) and the reasonable flexibility of the time element. Persistence of the time parameter in a subsidiary key

Even though the time element operates as a strict requirement in the comparative methods of the Agreement, this parameter is also projected —although with a different logic— onto the residual method, since, although the latter does not expressly reproduce the formula of “the same moment or an approximate moment”, its Interpretative Note makes it clear that the temporal factor does not disappear from the analysis, but retains relevance and is applied under a criterion of reasonable flexibility when circumstances prevent its strict observance (35)

Under this premise, this flexibility allows for adjusting the time requirement when its literal observance proves impractical, without distorting the method or disrupting the systemic coherence of the Agreement. At the same time, paragraph 3 of the Note defines the scope of this adjustment: with respect to identical goods, it allows for extending the time requirement, the country of production, and the use of previously determined values; with respect to similar goods, it allows for an equivalent extension; and, in the deductive method, it relaxes both the “same state” requirement and the “90-day” limit.

In all cases, the increased flexibility does not eliminate the requirements, but rather applies them more broadly to prevent the system from grinding to a halt. Thus, the Agreement articulates two complementary logics: a logic of strict comparability—focused on the time element—and a subsidiary logic of reasonable flexibility, aimed at preserving the system's operability without losing its anchor to real, verifiable, and economically relevant prices.

IX. Conclusions

The evolution of the topics addressed in this paper reveals a progressive shift from general formulations toward a structured regulatory system aimed at providing predictability and uniformity to the determination of customs value. In this process, the Brussels Definition of Value constituted an initial systematic effort, conditioned by a specific economic and institutional context and by a conception of value closely linked to state intervention and theoretical notions of price. Continuing this process, the adoption of the Agreement on Implementation of Article VII of the GATT in 1979 and its consolidation within the framework of the World Trade Organization following the Uruguay Round marked a turning point by establishing a model based on transaction value as its central axis, aimed both at standardizing disparate practices and at aligning the valuation regime with the dynamics of contemporary international trade.

Based on this historical and regulatory framework, it is clear that the different stages in the development of customs valuation differed not only in their value determination techniques but also in the importance assigned to structural elements of the system, among which the treatment of time occupied a unique place. In the Brussels Definition of Value, time was conceived in a structurally rigid manner, as the determination of value was linked to the moment when customs duties became due, granting the temporal element an immutable role regardless of the circumstances of the commercial transaction. Under this framework, such rigidity was sometimes perceived as a limitation in the face of market fluctuations, since variations in prices could cause the resulting value to not reflect the price actually agreed upon in the transaction.

Following this logic, the possibility that customs legislation might adopt different time criteria, as Herrera Ydañez explained, implied that the concept of time had to be definitively chosen and remain unalterable once established, as a necessary condition for preserving the internal coherence of the system. From this perspective, it reflected a conception of time as a technical criterion that, even if rigid in its application, was functional for the stability of the valuation regime in force during that period.

In contrast, in the contemporary model of the WTO Valuation Agreement, time remains relevant, but under a different logic depending on the applicable method. An examination of Article 1 demonstrates that the transaction value method was designed to be autonomous and independent of time considerations. The deliberate exclusion of the time element is not an omission, but rather a conscious normative decision intended to preserve the stability, predictability, and objectivity of the main method. Consistent with this approach, Explanatory Note 1.1 plays a crucial role in defining the scope of Article 1 and preventing the application of criteria specific to comparative methods. It clarifies that the time references in Article 1.2(b) are restricted to benchmark values ​​and do not condition the validity of the transaction value, thus avoiding the reintroduction of discretionary practices associated with previous models.

Based on this, the Agreement establishes a clear structural distinction. While the transaction value disregards the element of time as a condition of validity, time acquires an essential technical character in methods based on comparison. In this vein, in Articles 2 and 3, the requirement of the same or approximate moment operates as an economic standard intended to ensure that the references used reflect equivalent market conditions. Therefore, it is not merely a formal requirement, but rather a functional and case-by-case criterion that limits discretion in the selection of precedents and preserves the sequential coherence of the system. In accordance with this, the national, comparative, and EU case law analyzed shows that the Agreement deliberately avoided a rigid definition of the approximate moment to allow for a contextual application that preserves economic equivalence, taking into account the realities of the markets and the specific characteristics of each commodity and industry.

Therefore, the maximum time limits provided for in some legislations can operate as a guiding legal ceiling, but they do not replace or exhaust the economic analysis required by the system, prioritizing the greatest temporal and economic proximity to the operation being valued rather than the mere arithmetic verification of an enabling time limit, all without losing sight of a temporal hierarchy that prioritizes the exact moment and only secondarily the approximate moment, without enabling shortcuts towards residual methods.

This concept also extends to the deductive method. From this perspective, Article 5 reinforces the logic by establishing a tiered timeframe that distinguishes between the exact moment of importation, the approximate moment, and, only in the absence of both, an expressly established maximum limit. This prevents confusion between the concept of the approximate moment and the ninety-day period provided as a subsidiary rule, and avoids a mechanical application of the method. Furthermore, the super-deductive method demonstrates greater flexibility regarding the time element, justified by the nature of processing and marketing operations. Thus, the absence of strict limits does not imply arbitrariness, but rather a reinforced requirement for reasonableness, justification, and cooperation between Customs and the importer.

Finally, even though time operates as a strict requirement in comparative methods, this parameter does not disappear in the residual method. Instead, it operates under a different logic, characterized by the reasonable flexibility outlined in its Interpretive Note. Consequently, this flexibility does not eliminate requirements but rather enables their functional adaptation when literal compliance proves impractical without undermining the method's purpose. This preserves systemic coherence and ensures that, even in complex scenarios, the customs value maintains a reasonable, verifiable, and economically relevant link to real and comparable prices. Thus, the system articulates two complementary and coherent logics: a logic of strict comparability, in which time plays a central and defining role, and a subsidiary logic of reasonable flexibility, activated to prevent the system from grinding to a halt. Both converge on the same objective of neutrality, economic rationality, and limiting administrative discretion. 

From this final perspective, the Agreement continues to offer fertile ground for doctrinal and jurisprudential analysis, insofar as its correct application requires a systematic reading, attentive to the underlying economic logic and the purpose of each of its mechanisms. Far from being a closed regime, its interpretation and development constitute an ongoing challenge for operators, administrations, and courts, one that must be renewed in light of the transformations in international trade and the demands of a technically rigorous valuation system.

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Notes and references

1. Lascano, JC (2003). The customs value of imported goods. Buenos Aires: Osmar D. Buyatti, p. 26.

2. Sánchez, JI (2007). EU-CAN Cooperation Project. Trade-Related Assistance I. General Secretariat of the Andean Community. Lima: Bellido Ediciones, p. 19.
ALADI/SEC. (1983). Study 4: The Brussels Value Definition and the GATT Valuation CodeFebruary 10, 1983. “The Brussels Definition of Value and the GATT Valuation Code. Main Characteristics and Constituent Elements”: The basic principles that inspire both systems trace their origins to the Havana Charter, drafted by the United Nations Conference on Trade and Employment, and the General Agreement on Tariffs and Trade. Both instruments were directly related and had as their main objective the organization of international trade to promote economic development. Within their specific scope, both the Brussels Definition of Value and the GATT Valuation Code recognize the following as common basic principles: a) Customs value should be based on simple and equitable criteria that recognize international commercial practice; b) Valuation criteria should have a general scope of application; and c) The determination of customs value should be based, to the greatest extent possible, on commercial documents. 6. Apart from these basic principles common to both international systems, each, in its formulation and subsequent content, recognizes the following principles as the foundation of the system: a) The Brussels Definition of Value establishes that: – The concept of value should be easily understood by the importer and the customs administration and should allow for the rapid clearance of goods. – The valuation system should ensure that the importer acting in good faith is protected against unfair competition, whether fraudulent or not. b) The GATT Valuation Code establishes that: – The valuation system should be equitable, uniform, and neutral and should exclude the use of arbitrary and fictitious values. – The basis for determining customs value should be, to the greatest extent possible, the transaction value.

3. Lascano (2003), p. 27.

4. Lascano (2003), p. 29. Article 1(1) of the Brussels Convention stated that “For the purposes of applying ad valorem customs duties, the value of goods imported for consumption is the normal price; that is to say, the price that could be estimated to be set for these goods, at the time when customs duties become payable, as a result of a sale made under conditions of free competition between a buyer and a seller independent of each other.” Interpretative Note 1, for its part, established that “The time referred to in paragraph (1) of Article 1 may be, for example, the time of statutory presentation or registration of the declaration of goods for consumption, payment of customs duties or release of the goods.”

5. Zolezzi, D. (2003). Customs value. WTO Universal CodeBuenos Aires: La Ley, p. 6.

6. Zolezzi (2003), p. 6.

7. Basaldúa, RX (2011). Taxes on foreign trade. Buenos Aires: Abeledo Perrot, p. 160.

8. Lascano (2003), p. 34.

9. Lascano (2003), pp. 35–36.

10. Lascano (2003), p. 39.

11.Lascano (2003), p. 39.

12. Lascano (2003), p. 78.

13. HERRERA IDAÑEZ, R. (1963). Customs Value of Goods. Madrid, p. 79.

14. In the Republic of Argentina, Article 3 of Law 17.352 stated that “normal customs value is the price that is estimated to be set for the goods imported on the date of registration of the customs declaration…”. In the Eastern Republic of Uruguay, the time element was set at the date of numbering and registration of the customs clearance permit. González Bianchi, P. (2003). Customs value. Valuation of goods under the GATT/WTO system (Vol. I). Montevideo, p. 69.

15.Lascano (2003), p. 78.

16. Lascano (2003), pp. 49–50. The Technical Committee issues advisory opinions, comments, and explanatory notes after examining the specific technical problems raised by the parties as a result of the daily application of the valuation systems in their territories. None of these documents has a binding effect on the parties since they do not have the legal character of a rule, unlike the interpretative notes to the agreement incorporated in Annex 1. As the Technical Committee stated, none of the provisions of the agreement implies that the decisions of the Technical Committee have legal force for the signatories until they are incorporated into the national legislation of the signatories. The explanatory notes clarify the views of the Technical Committee on a question of a general nature that arises in relation to one or more provisions of the agreement, examine the commercial practices related to the question, and draw the necessary conclusions. 

Zolezzi (2003), p. 25. On the concept of an explanatory note, it clarifies the technical committee's views on a general issue raised in relation to one or more provisions of the agreement. An explanatory note may also examine trade practices related to the issue and draw the necessary conclusions. 

González Bianchi (2003), Vol. I, p. 84. An explanatory note will facilitate the application of a provision of the agreement to a number of commercial situations focused on that provision by customs administrations.

17. Adopted at the 2nd Session, 2 October 1981, 27.960. Text included as paragraphs 12 and 13, 7th Session, 2 March 1984, 31.460. Text included as paragraphs 6, 7 and 8, 7th Session, 2 March 1984, 31.460. Available at: https://www.wcoomd.org/es-es/topics/valuation/instruments-and-tools/advisory-opinions.aspx? 

18. Zolezzi (2003), pp. 57–61. The author indicates that the technical committee addressed the time factor in documents subsequent to explanatory note 11. The aforementioned author refers to two special cases: that of split files and that of the importation of used cars, discussed in commentary 6.1 and study 1.1, respectively. The real-world case he cites is also interesting.

19. Zolezzi (2003), p. 57. However, when prices rise, customs authorities must be cautious with sales whose dates predate the price increase. This is especially true when the time between the purchase date and the import date is longer than usual for the relevant industry. It could happen that an importer who purchased the goods after the price increase declares having acquired them earlier, thus simulating a transaction value lower than the actual one. In cases that raise doubts, customs authorities may investigate the veracity of the transaction date, in accordance with the provisions of Article 17 of the agreement and point six of Annex III.

20. Lascano (2003), pp. 126–127.

21. ALADI. Comparative study on customs valuation.

22. Lascano (2003), p. 201. The author points out that “in the case of commodities that are traded on open international markets, the respective prices can be easily determined to ascertain whether there were price fluctuations between the time of export of identical or similar goods and the date of export of the goods in the valuation process. In the case of finished or semi-finished industrial products, fluctuations are less frequent and therefore prices are more stable in the short and medium term.” 

González Bianchi (2003), Vol. II, pp. 43–45, in relation to the time element in articles 2 and 3 of the Agreement. 

23. Zolezzi (2003), p. 290. He cites Glashoff and Sherman, who argue that probably the most important factor to consider when deciding this issue is the degree of price stability or volatility. They say that if a choice must be made between a shipment of similar goods exported one week before the import or four shipments of identical goods exported one or two months prior, the latter should be chosen, provided that the market is not characterized by frequent price fluctuations.

24.General Secretariat of the Andean Community. (2014). Resolution No. 1684May 23, 2014. This regulation approved Community Regulation 571 on the Customs Value of Imported Goods, replacing the previous regulations, in particular Resolutions 846 and 1486. ​​This Regulation develops, among other things, the criteria applicable to the time element in valuation methods. In particular, Articles 39 and 43 govern its application in the transaction value methods for identical and similar goods, establishing as a starting point that the comparison must be made with goods exported at the same time or at approximately the same time as the goods being valued. Based on this rule, the Regulation sets a maximum limit of up to 365 calendar days to define the "approximate time," without prejudice to Member States being able to establish a shorter period, and recognizes the importer's right to object to the value determination by providing documentary evidence that demonstrates variations in commercial practices and market conditions that affect the price.

27.US Customs and Border Protection. (1999, April 12). HQ 546999: Request for Internal Advice; Transaction value of identical or similar merchandise; Del Monte Fresh Produce NA, Inc. https://rulings.cbp.gov/ruling/546999

28.Court of Justice of the Andean Community. (2014, September 17). Preliminary Interpretation 223-IP-2014. In this ruling, the Court interpreted the export requirement at the “same time or at approximately the same time” provided for in Articles 2 and 3 of the Agreement on Implementation of Article VII of the GATT 1994, incorporated into the Andean Community legal system through Decision 571 and its Community Regulation approved by Resolution 846. The Court specified that the concept of “approximate time” is not a merely formal or automatic reference, but a functional criterion that must be applied in a reasoned manner, taking into account the economic, commercial and market conditions existing at the time of export, in order to preserve the real comparability between the operations used as background and the operation being valued.

29.González Bianchi (2003), Vol. II, p. 67.

30. González Bianchi (2003), Vol. II, pp. 73–74.

31.González Bianchi (2003), Vol. II, p. 79.

32. Lascano (2003), pp. 211–212. Article 5.1 establishes a time limitation when it states that for the acceptance of the unit sale price, the transaction of the corresponding goods must be carried out at the time of importation of the goods subject to valuation or at an approximate time. The agreement does not provide details that allow clarifying the meaning of this expression, so it is an element that is related to the factual circumstances surrounding the particular case. However, considering that Article 5.1 (b) establishes that when it is possible to find operations within that time interval, those that are closest before 90 days have passed since said importation may be taken into consideration, the approximate time should reasonably correspond to a period of between 30 and 45 days before or after the importation.

33.Lascano (2003), p. 218.

34.González Bianchi (2003), Vol. II, p. 99.

35.US Customs and Border Protection. (2015, January 16). HQ H255619: Application for further review of protest no. 0401-14-100052; Price actually paid or payable; Dehydrated garlic. https://rulings.cbp.gov/search?term=H255619&collection=ALL&commodityGrouping=ALL&sortBy=RELEVANCE&pageSize=30&page=1.

In this ruling, Customs stated that, "[m]oreover, dehydrated garlic has a longer shelf life than the fresh asparagus in HQ 546217 cited above, making it reasonable to adjust the 'about the time of export' to a longer period. Accordingly, as a verified dehydrated garlic granules entry within reasonable proximity to the entry in question, using this previously accepted value is a reasonable adjustment to 19 USC § 1401a(c)."