Thirty-five years after the signing of the Treaty of Asunción, which gave birth to the Southern Common Market, it is appropriate to revisit one of the most sensitive—and least resolved—aspects of the integration process, referring to the commitments made regarding the free movement of goods and the persistence of economic policy instruments within the Argentine Republic, such as export duties.

Progressive integration

For the establishment of a Common Market among different countries, it is essential to fulfill temporally spaced stages that allow for the progressive achievement of this objective. In this sense, the Treaty of Asunción established a horizon, namely the formation of a common market, but it also enshrined—from its initial stage—precepts that define an economic spatial area with clear characteristics of a common customs territory.

Therefore, recognizing the progressive nature of the integration process toward a Common Market does not imply ignoring that, from its very inception, Mercosur has outlined structural elements that, first and foremost, necessitate the formation of a customs union. Consequently, while the projection toward a common market may require a longer development time, even exceeding that established by the Treaty itself, this should not be seen as justification for disregarding the applicable tariff regulations. Such regulations are essential to establishing the necessary foundations for a shared customs territory, applying the true meaning of what constitutes the free movement of goods. 

Therefore, it is necessary to differentiate between the concept of integration with a view to a common market, for which various measures are presupposed, and that which refers to the free movement of goods between member countries, without tariffs or restrictions on their products, in conjunction with the same common external tariff policy. 

Therefore, the consolidation of a common external tariff and the elimination of tariffs on intra-regional trade cannot be understood as exclusively future or conditional goals, but rather as essential components of the integration scheme that define a minimum standard of operation. Under this logic, the free movement of goods is not merely a programmatic objective, nor can it rely on a long-term projection, or worse, be subject to exclusively internal policies. On the contrary, it must be governed by an operational guideline that prioritizes and prioritizes trade relations between the Member States. 

The export right

To delve into the tax nature of export duties within the doctrinal universe and opinions on whether or not it constitutes a tax, at this stage of events and already vastly shaped by the very Supreme Court of Justice of the Nation (1) This is of little relevance. Clearly, this is based on the fact that export duties are a type of tax and, as such, fall within the scope of customs tariffs; and when referring to customs duties, both import and export duties are included.

In line with this, the Treaty of Asunción states that, during the transition period, the main instruments for the establishment of the Common Market will be: aA Trade Liberalization program, which will consist of progressive, linear and automatic tariff reductions, accompanied by the elimination of non-tariff restrictions or measures of equivalent effect, as well as other restrictions on trade between the States Parties, to reach by December 31, 1994, with zero tariffs, without non-tariff restrictions on the entire tariff universe (2); deals with all customs tariffs, not limited to import duties. 

Otherwise, the concept of “free movement of goods” would be flawed, as it would be possible to apply export duties. Ultimately, a free movement regime would not exist. While it might be possible, in a potential free movement scheme, to temporarily remove a specific set of goods from that regime, it would not be possible to limit the concept of free movement—in a customs union—based on allowing any customs duties. This would be illogical, given that the central tenet of the free movement of goods is the complete elimination of tariff barriers and quantitative restrictions (tariffs, quotas, equivalent measures) between member states, whether applied to imports or exports. 

El Dr. Enrique Barreira (3) Recall that Article 1 of the Treaty of Asunción established the creation of a common market as its objective, which implies the elimination of customs duties and non-tariff restrictions on the movement of goods and any other equivalent measures. It is worth noting that, as the Mercosur Tribunal held in Award 2/2006 (agreed upon by both parties), the verb "imply" mentioned in the heading of Article 1 of the Treaty of Asunción means "to contain" or "to include," indicating that the free movement mentioned therein constitutes an essential objective of the Agreement; so much so that a common market cannot be conceived without this requirement. Furthermore, the commitment assumed in the remaining provisions of the Treaty promotes the elimination of tariff and non-tariff barriers that impede or hinder this free movement.

Therefore, as also stated in Dr. Ricardo Basaldúa (4), The freedom of movement of goods referred to there is 'economic' freedom, that is, that the merchandise does not suffer direct or indirect restrictions to move, remain and be consumed, used or industrialized in the economic space into which it is introduced.

From this perspective, the imposition of export duties takes on a particularly problematic dimension. Even if there is no express prohibition in the original law, their application is hardly compatible with the notion of a common customs territory, since it introduces distortions equivalent to those that the system itself seeks to eliminate, in line with the concept of free movement of goods. 

Indeed, taxing intra-zone exports not only affects price formation and the economic decisions of operators, but also violates the principle of free movement by indirectly reintroducing obstacles to regional trade.

This implies that the progressive nature of the integration process cannot be invoked as justification for tolerating measures that, in practice, contradict its structural foundations. Therefore, this progressiveness must be understood as a process of deepening integration based on already established pillars, among which is the need to ensure conditions of exchange free from burdens that disrupt the logic of the regional market.

Consequently, maintaining the validity of export duties within the region implies not only a restrictive interpretation of the system's scope but also a conflict with the principles that gave rise to Mercosur. While the integration process—as stipulated in the Constitutive Treaty—allows for a transitional phase aimed at establishing a common market, this objective cannot be considered achievable if the free movement of goods remains merely a declaration, lacking effective implementation in practice. In this sense, a lack of coherence is observed between the proclaimed objectives and the measures actually adopted, and it is precisely in this divergence that the credibility and effectiveness of the regional integration process are compromised.

The Customs Union since the GATT

When analyzing the GATT Agreement, the joint interpretation of paragraphs 5(a) and 8 of Article XXIV of the GATT 1994 is particularly relevant, as both constitute a structural core of the legal regime applicable to customs unions in the multilateral trading system. 

Indeed, it can be observed that, on the one hand, paragraph 5(a)(5) establishes that the establishment of a customs union should not, on the whole, entail an increase in the general incidence of customs duties or a tightening of trade regulations with respect to third States, thus observing an external limit that preserves the balance of the system and prevents integration processes from becoming mechanisms of economic closure. While paragraph 8(6)(a) It defines a customs union as the replacement of two or more customs territories with a single one, requiring the elimination of customs duties and other trade restrictions on ––substantially–– all intra-zone trade, as well as the adoption of a common trade policy towards third countries.

From a systemic perspective, we believe that both provisions should be read in a complementary manner. That is to say, while paragraph 5(a) imposes a negative discipline—not to worsen access conditions for third parties—paragraph 8(a) establishes a positive mandate for substantial liberalization of intra-zone trade. Thus, taken together, these standards outline an integration model that not only requires relative external openness but also internal consistency in eliminating barriers to trade among the Member States.

It is appropriate to clarify here that, even though Article XXIV does not contain an express reference to export duties, this does not prevent us from analyzing its compatibility in light of the effects that such measures produce on intra-zone trade, particularly when they affect the formation of relative prices and the conditions of effective access to markets within the integrated area.

In this sense, a proper and functional interpretation of Article XXIV —focused on the objective of substantial liberalization of reciprocal trade— allows us to maintain that the concept of “other restrictive trade regulations” (see reference vi) contained in paragraph 8 a), should not be reduced to its formal dimension, but can encompass those measures that, even when adopted in the field of exports, generate effects equivalent to restrictions on intra-zone trade, by altering the competitive neutrality between the Member States, in order not to alter the conditions of competition or introduce distortions in the free movement of goods within the integrated space —the spatial scope of the customs union—.

Under this logic, the continued existence of instruments that, even without taking the form of import duties, negatively impact intra-regional trade—such as export duties—poses serious tensions with the standard of substantial liberalization required by Article XXIV (GATT). Indeed, such measures, by affecting relative prices and market access conditions in member states, can operate as indirect trade restrictions, undermining the purpose of the customs union as an area of ​​economic circulation free from substantial barriers. Consequently, their compatibility with the GATT regime must be analyzed in light of these structural principles, which prioritize openness, competitive neutrality, and regulatory coherence as pillars of the integration process.

To this must be added the commitment to a reasonable time frame stipulated by the GATT Agreement itself, which means that every plan and timetable must be established within a logical timeframe. This is evidenced by the fact that paragraph 5(c) requires that every provisional agreement include a plan and timetable for implementation within a “reasonable time frame,” a concept that the “Understanding on the Interpretation of Article XXIV of the General Agreement on Tariffs and Trade 1994” has specified as a maximum of ten years, except in duly justified exceptional circumstances. (7)

When these standards are applied to the Mercosur framework, established by the Treaty of Asunción, it becomes clear that the regional scheme was conceived precisely under the logic of a customs union, oriented towards the free movement of goods and the adoption of a common external tariff. However, more than three decades after its establishment, the persistence of measures that negatively impact intra-regional trade, such as export duties, reveals—from this perspective—a structural contradiction with the parameters of Article XXIV of the GATT. 

Indeed, long after the period that the GATT 1994 itself considers "reasonable" for consolidating the integration process has elapsed, invoking a phase of progressive integration is hardly legally sustainable. In this context, maintaining such instruments not only introduces distortions in the conditions of competition and the movement of goods within the bloc, but also tends to undermine the founding objective of creating an integrated economic space. Consequently, the current situation of Mercosur reveals a gap between the normative design of the multilateral system and its effective implementation at the regional level, which constitutes an additional reason to reconsider the compatibility of certain internal practices with the structural principles governing customs unions.

Recent evolution of the integration process: progress towards greater facilitation of intra-zone trade

In recent years, Mercosur has experienced a series of concrete advances that demonstrate a deepening of the integration process, particularly regarding trade facilitation and the reduction of transaction costs. These developments, far from being mere technical innovations, reflect a qualitative transformation in how the movement of goods within the bloc is conceived, further strengthening provisions that harmonize integration.

Therefore, it is appropriate to state some of these measures:

• Mercosur Trade Facilitation Agreement – ​​ratified by Argentina Law 27.766(8)–The objective is to simplify and standardize customs procedures among the States Parties, with the aim of reducing time and costs and seeking the elimination of charges on services. It is established that each State Party guarantees, in accordance with Article VII of the GATT 1994, including its notes and supplementary provisions, that all fees and charges of any kind, other than import and export duties, taxes on or in connection with imports or exports, will be limited to the approximate cost of the services rendered, will not be calculated on an ad valorem basis, and will not constitute indirect protection for domestic products or a tax on imports or exports for fiscal purposes. With respect to Argentina, this is the statistical fee (9).
• Advance ruling ––equal treatment––: Each State Party shall issue, prior to the importation of goods into its territory, an advance ruling upon written request from an importer in its territory or from an exporter or producer in the territory of another State Party, containing all the necessary information. In the case of an exporter or producer in the territory of another State Party, the request for advance ruling shall be made in accordance with the internal rules and administrative procedures of the territory of the State Party to which the request is addressed.. (10)
• Common documentation and data: The Member States shall apply the agreed common data model to integrate declarations of customs destinations and operations within Mercosur, in line with the WCO data model (11) for both imports and exports, in order to achieve rapid release of goods, reducing compliance time and costs for operators. This includes adding automated procedures to expedite the import, export, and transit of goods.
• Technological and electronic systems: The States Parties shall use information technologies that expedite procedures for the import, export, and transit of goods. With regard to exports, it was established that efforts should be made to ensure that the entities responsible for issuing international freight transport permits issued under the international agreements signed in this area advance in computer integration, in order to facilitate the exchange of the respective permits. This also includes a commitment to simplified customs clearance. (12)
• New Mercosur Rules of Origin: The certificate of origin known as ROM,(13) as referred to in the Lic. Andrea Russo, has generated a significant change by replacing all previous regulations and allowing greater flexibility in procedures.(14)Warning from our view, that it is not a simple technical innovation, but the clarity in its objective of deepening integration in which the circulation of goods is conceived under parameters of simplification, traceability and cost reduction incompatible with the persistence of distortive tax burdens.
• INDIRA System – This system facilitates the exchange of information from customs records within Mercosur. It was launched in 2004 by GMC Resolution No. 54/04. This system has evolved, as explained below. Dr. Hector Juarez Allende, indicating that, through Decision (CMC) No. 26/06, the current “Agreement on Cooperation, Exchange of Information, Consultation of Data and Mutual Assistance between the Customs Administrations of Mercosur” was put into force within the MERCOSUR framework, which repealed the previous CMC Decisions No. 01/97, 13/04 and 19/05. Noting that, through CMC Decision 01/08, the Specifications of Technical Characteristics of the Computer Infrastructure for the Electronic Exchange of information on Customs operations through the INDIRA System were established (15).

Based on these and other provisions not mentioned here, the States Parties reaffirm the objective of integration, harmonizing specific guidelines to consolidate joint efforts to streamline and simplify procedures related to the import and export of goods. This will be achieved through the development and implementation of procedures designed to facilitate the cross-border movement and circulation of goods, thereby promoting legitimate and secure trade and reducing time and costs within the Mercosur territorial scope. This is also a sphere where, since the founding of the Asunción Agreement, the free movement of goods has been paramount.

At this point, it is important to clarify that the reference to the measures adopted in recent years—both those related to trade facilitation and those concerning the operational implementation of the rules of origin, among others—should not be understood as a mere enumeration of technical or instrumental tools. On the contrary, these decisions reflect a clear orientation of the Member States toward deepening the harmonization of standards within the Mercosur customs framework. This aims to reduce the time, costs, and operational burdens associated with intra-regional trade, based on operational schemes that rely on what is understood as "facilitating." These actions are designed to strengthen the competitive advantages of the Member States and those involved in both imports and exports. 

Recalling, as has been referred to Dr. Juan Patricio Cotter Upon analyzing the Trade Facilitation Agreement (WTO – Law 27.373), it becomes clear that, ultimately, facilitation aims to simplify, standardize, harmonize, and automate the procedures applied to international trade, with the goal of expediting the movement, release, and clearance of goods. This entails generating efficient, effective, and agile procedures so that shipments take the minimum time necessary for proper inspection, according to the circumstances of the operation, thereby reducing direct and indirect costs associated with international trade. This is the objective of facilitation: to reduce timeframes and costs. Furthermore, the Dr. Cotter It is noted that the Facilitation Agreement provides a framework of rights and obligations that tend to improve border procedures in order to reduce time and costs, generating competitive improvements for States and individuals. 

In this sense, such measures not only optimize trade dynamics, but, in our view, consolidate a legal and economic standard that would not only be incompatible, but openly contradictory with the continued existence of taxes that increase costs or distort their formation, as occurs with the application of intra-zone export duties, thus affecting competitiveness, which on the other hand is intended to be strengthened through the uniform application of operational and simplification measures in the search to reduce times and costs in Mercosur.

It is necessary to introduce a conceptual clarification to properly define the scope of trade facilitation measures in relation to customs tax authority. Generally speaking, the implementation of instruments aimed at simplifying, harmonizing, and modernizing customs procedures does not, in itself, preclude the possibility of establishing or maintaining taxes on foreign trade, as both operate under different regulatory frameworks.

However, we believe that this premise needs to be qualified when applied to the Mercosur integration process. Indeed, the bloc's institutional framework—established through conventional commitments undertaken by the Member States—is not limited to mere intergovernmental coordination, but rather, at least in its original normative design, is oriented towards the formation of an integrated economic space, characterized by the non-application of customs duties, the elimination of restrictions on intra-zone trade, and the adoption of common policies. 

Thus, the determination of harmonizing legislative acts indicates the elimination of those internal provisions of the countries of the bloc, seeking to standardize common norms in order to guarantee the integration process as well as the free movement of their products.

In this context, facilitation measures cannot be conceived in isolation or neutrally, but must be interpreted as functional instruments for achieving the structural objective of the integration process, which is: the consolidation of the free movement of goods within the region. From this perspective, the requirement of homogeneity is not limited to merely operational or procedural aspects, but necessarily extends to the applicable substantive legal framework, including—unavoidably—the tax treatment of intra-regional trade.

Under this systematic and teleological approach, it can be argued that what in an initial stage of the process might have been characterized as an objective of progressive realization must now be reinterpreted as a mandate for effective implementation. This is because the consolidation of a common market—as both a legal and economic category—is incompatible with the continued existence of instruments that introduce distortions into the conditions of competition and the movement of goods.

Consequently, the persistence of export duties in intra-regional trade appears dissonant within Mercosur's normative and axiological framework. Such duties not only undermine fiscal neutrality and a level playing field among economic operators, but also contradict the principle of free movement that informs the integration process. Therefore, their maintenance cannot be considered a legitimate manifestation of gradualism, but rather an exception that weakens the system's internal coherence and compromises the effectiveness of the objectives pursued by the founding agreement.

This allows us to observe a paradigm shift, starting from the fact that the Mercosur integration process has ceased to be predominantly programmatic to assume an operational dimension, in which the free movement of goods is materialized through concrete instruments that aim to neutralize costs and optimize the commercial dynamic throughout the bloc, while on the other hand, export duties are imposed.

In this context, the persistence of export duties applied to intra-zone trade appears contradictory to the reasonableness of these advances. While the system is moving towards simplification, digitalization, and debureaucratization of trade with a view to reducing import and export times and costs—ultimately consolidating the free movement of goods with uniform measures within a single customs area—the continued existence of tariffs that directly affect price formation introduces a structural distortion that compromises the coherence of the integration process. Consequently, the recent evolution of Mercosur not only reinforces the centrality of the principle of uniformity of measures to strengthen the free movement of goods, as agreed upon in the framework agreement, but also demands a critical reconsideration of those practices that are incompatible with its effective consolidation, such as the application of export duties to intra-zone exports.

Whirlpool Puntana SA Ruling

The doctrine established by the Supreme Court of Justice of the Nation in the precedent Whirlpool Puntana SA v. General Directorate of Customs (17) has constituted, for more than a decade, the dominant interpretative framework for export duties within Mercosur. However, the time elapsed since its enactment and, fundamentally, the evolution experienced by the regional integration process, necessitate a review of its foundations. 

Beyond whether or not to follow the guidelines that served at that time to decide as the highest Court of the Nation has done, more than ten years later, it is clear that concrete events have occurred, both from the legal standpoint and from the integration process, that lead to a different analysis and the need to review this criterion.  

Indeed, the ruling was issued in a context where the Mercosur framework could perhaps still be considered to be in its early stages of consolidation, with limited progress in the effective implementation of instruments guaranteeing the free movement of goods. Under these conditions, the Court adopted an interpretation that prioritized the absence of an express prohibition in the bloc's original law, thus seeking to recognize Argentina's right to apply export duties.

However, the current reality of the integration process reveals a qualitative shift that cannot be ignored. Over the past few years, Mercosur has made progress in implementing concrete mechanisms aimed at applying uniform measures across the bloc to facilitate and deepen intra-regional trade. These measures include the progressive digitization of origin certification instruments—such as the electronic certificate of origin—the simplification of customs procedures, and the consolidation of practices aimed at reducing transaction costs and strengthening the system's predictability, reinforcing guidelines that impact the free movement of goods by saving time and costs.

These developments are not mere administrative innovations, but concrete manifestations of an integrationist will aimed at the effective formation of a homogeneous economic space. In this sense, confirming the principle of integration, and reinforcing the framework upon which the initial Agreement was based—namely, the free movement of goods—cannot be conceived, at present, as a programmatic objective, but rather as an operational guideline. This represents a deepening of the process that directly impacts the interpretation of the obligations assumed by the Member States, bearing in mind that the free movement of goods rests upon it, without the possibility of limiting this action with restrictive and/or internal tariff measures. Thus, in this new scenario, where Mercosur has advanced towards cost reduction, the digitalization of controls, and trade facilitation, it is conceptually contradictory to allow the continued existence of tariffs that affect price formation and reintroduce distortions equivalent to those that the integration process itself sought to eliminate from its inception.

Therefore, the interpretation adopted in the Whirlpool precedent, based on the absence of an express prohibition, would require review in light of a dynamic and evolving interpretation of Mercosur law. Regional integration and the full concept of free movement of goods cannot be understood through a static reading of its founding norms, but rather demand attention to its effective development and the commitments that, in practice, have consolidated a more demanding standard of free movement of goods, both in terms of imports and exports. This is in addition to the requirement of timeliness, which stipulates that the implementation of what was expressly agreed upon by the Member States in the parent Agreement, regarding the non-application of customs duties and the elimination of restrictions, must be carried out within a reasonable timeframe. 

In short, persisting with an interpretation anchored in an earlier stage of Mercosur means ignoring the evolution of the system and limiting its capacity to project a true Common Market. From this perspective, there is no perceived need for a new agreement or an expansion of the existing one, since the Treaty of Asunción is clear in its purpose of establishing a common market. Indeed, the text itself states that:It implies the free movement of goods, services and factors of production between countries, through, among other things, the elimination of customs duties and non-tariff restrictions on the movement of goods and any other equivalent measure.”(18)

However, although the Supreme Court of Justice of the Argentine Nation has indicated —in the Whirlpool precedent— that there is no express rule prohibiting the application of export duties in intra-zone trade, the truth is that the Treaty does not formulate its provisions in direct prohibitive terms either, but establishes elimination obligations aimed at guaranteeing the free movement of goods.

In this sense, the explicit reference to the elimination of customs duties and any measure of equivalent effect allows us to maintain that the system's objective is not limited to a formal category of taxes, but rather extends to the elimination of those instruments that, due to their impact, could affect intra-zone movement. Under this interpretation, the logic of the Treaty leads to prioritizing a scheme of not imposing burdens that hinder reciprocal trade, in line with the aim of consolidating an integrated economic space. This is expressly agreed upon—as an objective—when it refers to: “free movement of goods” and “elimination of customs duties and restrictions.” Consequently, the Treaty that gave rise to Mercosur stipulates the non-imposition of duties to achieve this objective, whether for imports or exports.

Conclusion

The integrationist ideal that inspired the Member States—based on the progressive elimination of restrictions on intra-regional trade and the consolidation of a common market—has coexisted, not without friction, with practices that respond to domestic fiscal and regulatory needs. In this context, export duties emerge as a tool of this tension, as they raise important questions about their compatibility with the bloc's principles and objectives.

The issue is not merely technical or circumstantial. On the contrary, it calls into question the very degree of development of the regional framework and forces us to ask whether, more than three decades after its creation, Mercosur has managed to consolidate a true common economic space, or whether mechanisms persist, in new forms, that limit the full implementation of its founding principles, contradicting the fundamental principle of the free movement of goods.

From a strictly regulatory perspective, the analysis of export duties within Mercosur requires, based on the commitments undertaken in the Treaty of Asunción, particularly regarding the elimination of customs duties and restrictions on intra-zone trade and the actual establishment of a Common Market, the existence of a customs area in which the free movement of goods prevails without exception.

In this context, the continued existence of export duties—validated by the doctrine established by the Supreme Court of Justice of the Nation—effectively distorts the objectives pursued by the Member States, to some extent due to this position frozen in time. Indeed, while the bloc projects itself externally as an advanced integration process, the persistence of internal regimes that hinder free movement within the zone reveals a structural contradiction that weakens its credibility and coherence.

Consequently, accepting the continued validity of export duties in intra-regional trade implies upholding a fragmented conception of the integration process, incompatible—as indicated in previous points—with the homogeneous and harmonized regulatory and operational advances achieved in trade facilitation, such as the simplification of customs operations and frameworks related to the concept of a customs union. These advances reflect the common will of the Member States, constituting an important legal basis for affirming that a common, agile customs environment should prevail in Mercosur, reducing both import and export times and costs. This consolidates the integration concept, resulting in a clear framework of a uniform customs environment, corresponding to the non-application of customs duties, whether import or export, in order to guarantee the effective free movement of goods.

In this scenario, the Whirlpool precedent, regardless of the merits of its reasoning, shows signs of being outdated in light of the evolution of Mercosur law and its current regulatory framework. Indeed, maintaining this position would consolidate an interpretation that is hardly compatible with the current reality of the integration process. In this context, and considering subsequent regulatory and operational developments, it can be argued that its conclusions have lost relative relevance, as they correspond to a stage of the integration process that does not reflect the current demands for coherence and deepening of the regional framework. Thus, we are faced with a ruling that has lost its relevance and interpretive validity, necessitating its review in light of the evolution of the integration process.

While the precedents of the Supreme Court of Justice of Argentina are binding on lower courts, this does not preclude the need to review existing doctrine in light of new arguments and the evolution of applicable law. In this regard, such a need becomes especially relevant given the lack of a clear definition from the political authorities to guide the process toward the effective implementation of the principle of free movement of goods among the member countries. In particular, this issue concerns the compatibility of certain instruments—such as export duties—with the commitments made regarding the elimination of customs duties, non-tariff barriers, and other measures of equivalent effect, the central focus and raison d'être of the integration process within the framework of a common customs area in Mercosur. 

Notes and References

1. CSJN, «Camaronera Patagónica SA v. Ministry of Economy and others re: amparo» (15/04/2014).
2. Treaty of Asunción – Chapter I – Purposes, Principles and Instruments – Article 1.
3.  BARREIRA, Enrique, “The illegitimacy of export duties in intra-zone trade of Mercosur”, Journal of the Argentine Institute of Customs Studies, p. 117.  
4.  BASALDÚA, Ricardo Xavier, «Mercosur and Integration Law», Buenos Aires, Abeledo Perrot, 1999, (referenced by Dr. Enrique Barreira – The illegitimacy of export duties in intra-zone trade of Mercosur”, Journal of the Argentine Institute of Customs Studies, p. 113.)   
5.  Article XXIV, paragraph 5(a): “5. Accordingly, the provisions of this Agreement shall not prevent, between the territories of the Contracting Parties, the establishment of a customs union or a free trade area, nor the adoption of a provisional agreement necessary for the establishment of a customs union or a free trade area, provided that: (a) in the case of a customs union or a provisional agreement aimed at the establishment of a customs union, the customs duties applicable at the time of the establishment of such union or the conclusion of the provisional agreement are not, on the whole, with respect to trade with the Contracting Parties which are not part of such union or agreement, of a higher general incidence, nor are the other trade regulations more stringent than the trade duties and regulations in force in the constituent territories of the union before the establishment of the union or the conclusion of the provisional agreement, as the case may be.
6.  Article XXIV, paragraph 8(a)(1): 8. “For the purposes of this Agreement, (a) a customs union shall mean the replacement of two or more customs territories by a single customs territory, such that: customs duties and other restrictive trade regulations (except, to the extent necessary, restrictions authorized under Articles XI, XII, XIII, XIV, XV and XX) are eliminated with respect to the substance of trade between the constituent territories of the union or, at least, with respect to the substance of trade in products originating in those territories;”
7.  Point 3: 3. “The “reasonable period” referred to in paragraph 5(c) of Article XXIV shall not exceed 10 years except in exceptional cases. Where Members that are parties to an interim agreement consider that 10 years would be an insufficient period, they shall give the Council for Trade in Goods a full explanation of the need for a longer period.” ANNEX 1, ANNEX 1A, MULTILATERAL AGREEMENTS ON TRADE IN GOODS, General Interpretative Note to 1st.
8. Law 27.766 (BO21/10/2024).
9. Article 13, point 1 (Law 27.766).
10.  Article 8, points 1 and 2 (Law 27.766).
11.  Article 7, point 1. (Law 27.766)
12.  Article 5, point 1. (Law 27.766).
13. Decision 05/2023 of the Common Market Council (CMC). The ROM is a set of rules and procedures that establish the conditions that a product must meet to be considered originating from a MERCOSUR Member State.
14.  RUSSO, Andrea, “24 hours before the entry into force of the new MERCOSUR Rules of Origin: Some answers to questions about the operation and the transition”. Customs News (19/07/2024).
15.  JUÁREZ ALLENDE, Héctor, “INDIRA. The Information Exchange System of Customs Records in MERCOSUR.” Customs News. (5/01/2023).
16.  COTTER, Juan Patricio, “Trade Facilitation and Advance Rulings”, Customs News (12/04/2024).
17.  CSJN, “Whirlpool Puntana SA (TF 21.671-A) v. General Directorate of Customs”. (11/12/2014).