Importing from China into Mercosur: what is the same and what changes between Brazil, Argentina, Paraguay and Uruguay

There are two wrong readings of Mercosur, and they cancel each other out expensively. The first is to think it is a single market, and to find out on arrival that a product certified in Brazil does not enter Uruguay without local registration. The second is to think they are four unrelated worlds, and to redo from scratch classification and testing work that was already done.

The truth is far more useful than either: the expensive, slow part is shared, and the part that changes is known and finite. This guide maps exactly where that line runs, separating what has been checked against official sources from what still requires local confirmation.

What is genuinely shared: the classification and the tariff

The Common External Tariff was created by Decision 22/94 of the Common Market Council and runs on the Mercosur Common Nomenclature, the eight-digit code the four countries use to say what a good is. Each code carries a duty rate, and that rate is, in principle, the same across all four.

The practical consequence is large and little explored: the work of classifying a product bought in China is done once and holds for all four markets. Anyone who has been through a reclassification knows that this is precisely the part that eats weeks of technical analysis and that generates the most expensive tax risk. If you already have that work done for Brazil, as the guide to NCM and tariff classification describes, it is not lost when you cross the border.

In the same way, almost all the origin paperwork works in all four: commercial invoice, packing list, bill of lading, certificate of origin and the Chinese laboratory's test reports describe the goods, not the destination. That is why the body of the sourcing work, the part done on the Chinese side, What does change is the declared origin, and swapping China for another country of shipment only adds up when that origin survives a check.

Where the common stops being common: the exception lists

Here is the first surprise, and it dismantles the naive reading of the word common. Each country is entitled to a national list of exceptions to the common tariff, the LETEC, with a defined number of codes it may tax differently from the rest of the bloc.

The current figures, and the asymmetry they reveal:

Two details make this operational rather than merely curious. First, countries notify the composition of the list to the Mercosur Secretariat before 31 January and 31 July each year, meaning the list moves twice a year and is not a permanent figure. Second, the code rotation rule, which had been suspended until the end of 2025 and allowed the whole list to be renewed, came back into operation in 2026. In April 2025 the four countries were further authorised to widen their lists by up to fifty codes.

The reading that matters to a buyer: if your product sits on one country's exception list, its rate there is not the bloc rate, and it can be considerably lower or considerably higher. It is the first place to look when comparing the viability of the same product in two neighbouring markets, and it is a check to be redone every six months, not once in a lifetime.

Four customs doors, and none of them alike

If the classification is shared, the way in is not. Each country has its own system, its own registration and its own set of deadlines, and all four went through relevant changes in the last two years.

Brazil: the DUIMP replacing the DI

Brazil is in the middle of its biggest system change in decades. The DUIMP, the single import declaration, gathers into the Single Portal what used to be separate declaration, licence and documents, and has been replacing the Siscomex DI in stages. The official shutdown schedule advances through 2026, with 1 December 2026 marked as one of the larger milestones, and the agency itself warns that the dates depend on private sector validation and may be revised.

For an importer, the practical effect is that operations that ran on autopilot for years now require product and catalogue registration before shipment. It is not a change of form, it is a change of moment: part of the work that used to wait for arrival moves to before the purchase.

Argentina: one step fewer since 2025

Argentina came out of a decade of prior licensing regimes that kept changing name and acronym, and that were the region's largest source of unpredictability. In 2025 the government repealed the Sistema Estadístico de Importaciones, the SEDI, by joint resolution of ARCA and the Secretariat of Industry and Trade. Since 26 February 2025, goods no longer need that prior declaration in order to be cleared.

The lineage is worth recording, because it still shows up in out-of-date texts: the SEDI had replaced the SIRA and the automatic and non-automatic licensing scheme, and had come into force in December 2023. Anyone reading a guide written before 2025 will find requirements that no longer exist. The customs and tax authority today is ARCA, which succeeded AFIP.

Paraguay: everything through the single window

Paraguay concentrates in the Ventanilla Única del Importador, the VUI, run by DNIT, the authorisations that are not customs matters as such. Access requires the single importer registration, and the system talks to SOFIA, which is the customs platform. Procedures from bodies such as INTN, DINAVISA, INAN and the Asunción municipality run through the VUI, and since February 2026 so do those of MADES, the environment ministry.

The design is the opposite of the Brazilian one in spirit: instead of a single system absorbing everything, a window that routes the request to the right agency.

Uruguay: the VUCE, and an integration that moved forward

Uruguay operates through the Ventanilla Única de Comercio Exterior, the VUCE, together with the National Customs Directorate, and the customs declaration is the single customs document. Integration between the VUCE, customs and URSEA, the energy regulator, was formalised in a cooperation agreement in 2024, which in practice reduced the paper shuttling between agencies.

Four sets of agencies: the map of who rules what

This is the table to keep. It does not replace consulting the agency, but it settles the question that stalls the start of any project, which is whom do I ask.

There is a difference of philosophy built into that table, and it is worth more than the names. In Brazil, a technical standard usually becomes mandatory through a conformity assessment programme, and the list of products with INMETRO requirements is long and detailed. In Paraguay, an INTN standard is in principle voluntary, and only becomes mandatory once a technical regulation makes it so. These are two regimes of very different thickness, and that explains a good part of what is observed in the region's trade flows.

What changed between 2025 and 2026, and why it matters now

Three verifiable changes have reshaped the ground recently, and all three push in the same direction, which is to accept more work done abroad and repeat less testing.

• Argentina, the end of the SEDI. Since February 2025 there is no longer a compulsory prior declaration for clearance. An entire step left the path.
• Argentina, foreign certificates in electrical safety. Resolution 16/2025 of the Secretariat of Industry and Trade updated the technical regulation and began easing acceptance of certificates issued abroad, so as not to pay twice for a test already run by an accredited laboratory or certification body outside the country. Resolutions 16/2025, 17/2025 and 236/2024 set the scope for electrical equipment, machinery and installation material.
• Argentina, a new type approval regime for telecommunications. ENACOM Resolution 57/2026, published in February 2026, restructured type approval and came into force on 1 September 2026. It creates certification agencies, which issue certificates on the basis of a laboratory report, introduces registration by product family, and now requires online listings to display the RAMATEL registration number. Existing registrations remain valid for three years from publication.

Add Brazil's transition to the DUIMP and the picture is clear: all four countries are reworking their systems at the same time, and an import project designed with 2023 information will meet requirements that no longer exist and miss facilities that have come into being.

What this changes in your buying in China

All of that architecture comes down to a short list of decisions taken before production, with the factory, and not afterwards, with the cargo stuck. This is where the difference between the four countries turns into cost or turns into scale.

01 Decide the countries before approving the sample

If there is a real chance of selling in more than one country of the bloc, that has to be on the table before the mould is cut. Label, manual, plug and voltage are production decisions, not packaging ones, and changing them later costs a batch.

02 Treat plug and voltage as specification, not detail

Brazil has a plug standard of its own, that of NBR 14136, which its neighbours do not use, and it lives with two mains voltages depending on the region. Argentina uses a different standard, that of IRAM 2073. Uruguay and Paraguay work with other formats again. Confirm the exact standard of each destination country before closing, because that is the most banal physical difference and the one that sends most containers back.

03 Order the test once, in a form that serves more than one country

Much electrical safety testing follows international standards, and the report from an accredited laboratory is the document that travels. With Argentina beginning to ease acceptance of foreign certificates, it is worth designing the test package with reuse in mind, rather than ordering one package per country. Registration remains national, but the test may not need repeating.

04 Separate what is registration from what is labelling

Registration is a process, it takes time and depends on the agency. Labelling is production, it takes a file and depends on the factory. Confusing the two is what makes somebody postpone a purchase over a language requirement that a supplier could have settled in a week.

05 Register in each country, and count that lead time

Importer registration is national in all four: the Radar in Brazil, registration with ARCA in Argentina, the single importer registration in Paraguay, registration with Uruguayan customs. None of them is automatic, and all of them go into the calendar. Anyone without their own structure in one of the countries can operate through a partner, on the logic of import on behalf of a third party.

06 Check this half-year's exception list

Before comparing the viability of the same product in two countries, check whether the code sits on either one's LETEC. It is a check that takes minutes and can change the whole calculation, and it has to be redone every six months, because the list is updated in January and in July.

The opportunity almost nobody works

It is worth ending on the positive side, because it is bigger than it looks. Importers in the bloc tend to think about a single country, and so buy in volumes that give them no negotiating power at all in China. The map of industrial clusters shows why that is expensive: in almost every category there is a quantity threshold above which the price changes band and the factory starts treating you differently.

Adding two or three Mercosur countries into a single order is one of the cheapest ways to reach that threshold, and it requires no new partner and no new structure: it requires handling the differences at origin. The classification is already shared. The testing is reusable. What changes is registration, labelling and importer registration, and all three are known, finite and plannable.

What cannot be settled at a distance is the other half: confirming that the factory will produce three label variants in the same batch without changing the price, that the right plug went onto each pallet, and that the paperwork left with the description each customs authority expects to see. That is verified on the factory floor, before shipment, and it is exactly what pre-shipment inspection exists to catch. To fit the operation into the year, with trade fairs and production shutdowns on the same map, the 2027 sourcing plan shows from when each decision has to be made.

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