Triangular transactions (triangulation) UK–PL–third country — VAT and documents after Brexit

What an EU triangular transaction and the simplified procedure are

An intra-Community triangular transaction (WTT) is a pattern in which the same goods are the subject of two successive supplies — from the first seller (A) to the intermediary (B), and then from the intermediary to the final customer (C) — where the goods are transported directly from A to C, bypassing the intermediary's warehouse. The definition of WTT is set out in Article 135 of the Polish VAT Act, and its EU basis is Article 141 of Directive 2006/112/EC.

The heart of the arrangement is the simplified procedure: if the statutory conditions are met, the VAT on the supply to the final customer is accounted for by that final customer (C) in the country where the transport ends. As a result the intermediary (B) does not have to register for VAT in the country of destination of the goods — a real administrative saving. The conditions include, among others:

• three taxable persons registered for intra-Community transactions in three different EU Member States;
• the goods transported directly from the first supplier to the final customer;
• the intermediary uses an EU VAT number issued by a Member State other than the country of destination and is not established in that country;
• the final customer uses the EU VAT number of the country where the transport ends and is designated as the person liable to account for the VAT.

In addition, the invoice issued by the intermediary to the final customer must — in accordance with Article 136 of the Polish VAT Act — contain the appropriate annotation (a reference to the simplified procedure under Articles 135–138 of the Act or Article 141 of the Directive) and a statement that the tax will be settled by the last customer in line, together with the EU VAT numbers of the intermediary and the customer. The absence of these elements rules out applying the simplification. This article reflects the legal position as at 2026-06-13. Contact a customs agency or tax adviser before taking any action.

Brexit: why a company from the United Kingdom (GB) drops out of triangulation

This is where the crux of the problem lies. The simplified procedure is an intra-EU mechanism — it requires three taxable persons in three different EU Member States. Since 1 January 2021 the United Kingdom (England, Wales, Scotland — hereafter GB) has been, for VAT purposes, a third country. A GB VAT number is not an EU VAT number, so a UK entity cannot play any of the three roles in an EU triangulation.

The practical consequence: a setup that before Brexit could be settled as a simple triangular transaction now — if a GB company takes part in it — breaks down into export and import with customs clearance. Where VAT and the correct invoice annotation used to suffice, there are now two separate customs-and-tax events.

Technical exception: if a company established in GB holds a separate VAT registration in an EU Member State (other than the country of dispatch and destination), it may use the simplified procedure on the basis of that EU number — but it then acts as an EU entity, not "on the GB number".

What takes the place of triangulation in the UK–PL–third-country setup

When the chain includes a GB entity without an EU registration, the transaction has to be "broken down" into customs legs:

• The EU → UK leg is treated as an export at the 0% rate (once proof of export is obtained) and an import into the UK (duty per the tariff + import VAT, usually settled through PVA).
• The UK → EU leg in turn is an export from the UK and an import into the EU country (e.g. into Poland), with customs clearance and import VAT in the country of importation.
• Who the importer is and who clears the goods is settled by the Incoterms: under DAP the buyer arranges import clearance, under DDP the seller does (which usually requires a registration or a representative in the country of import).

In short: triangulation as a VAT simplification is ruled out here, and its place is taken by the normal customs logic of export and import — with documents, EORI and VAT accounting on both sides of the border. We explain the difference between duty and VAT in a separate article on duty and VAT.

Northern Ireland (XI) — an exception for goods, but with a caveat

Northern Ireland has a special status. Under the Windsor Framework and the earlier Protocol, for trade in goods Northern Ireland remains within the EU VAT area. Businesses use a number with the XI prefix (instead of GB), which is visible in the EU VIES system, and an XI EORI number is used for customs clearances.

In principle this means that an entity from Northern Ireland (XI) can take part in the EU simplified WTT procedure for goods — unlike GB. Caution is still needed, however: acceptance of the XI prefix for triangulation purposes varies between EU Member States, and some administrations take different approaches to identifying UK and Northern Irish transactions. So treat the XI status as "technically EU, but requiring verification" — it is worth confirming each such transaction with a local tax adviser in the counterparty's country. We cover the GB–NI rules in more detail in our article on the Windsor Framework.

GB versus XI — a quick comparison

• GB (England/Wales/Scotland): a third country for VAT, not in VIES, no participation in the simplified WTT procedure, EORI with the GB prefix.
• XI (Northern Ireland): within the EU VAT area for goods, number visible in VIES, in principle participation in WTT possible (subject to acceptance of XI), EORI with the XI prefix.

Chain transactions and the allocation of transport ("quick fixes")

Where a chain involves at least three participants and the transport takes place directly from the first to the last, only one supply can be the "moving" one (at the 0% rate as an intra-Community supply or an export) — the others are "stationary" (domestic). The rules for allocating transport in intra-EU trade were harmonised from 1 January 2020 by Article 36a of Directive 2006/112/EC (the so-called quick fixes): as a rule the transport is allocated to the supply to the intermediary, unless the intermediary gives the supplier the VAT number of the State from which the goods are dispatched — in which case the moving supply is the one from the intermediary.

An important caveat: the quick fixes rules concern intra-EU legs. Where GB is involved, the EU–UK leg is an export/import, not an intra-Community supply — and the quick fixes rules do not apply to it.

Documents in a chain involving the UK

In a chain transaction involving the United Kingdom you need to prepare a full set of customs documents and confirmations:

• Commercial invoice for each leg — with the parties' details, a description of the goods, the value, the Incoterms and the country of origin.
• Export declaration and proof of export — on the EU side the IE599 message confirming export (the condition for the 0% export rate); export from the UK is carried out in the CDS system.
• Import declaration in the country of importation — import into the UK requires a GB EORI number, and import VAT is settled through PVA or on the basis of a C79 certificate; import into Poland/the EU — clearance and import VAT with an EU EORI.
• EORI numbers — movements through the United Kingdom require a GB EORI, and clearances in the EU require an EU EORI; an entity operating on both sides needs both, or works through a customs agency.
• Proof of origin (TCA) — if you want to use the zero customs rate under the UK–EU agreement, you need proof of origin, usually in the form of a statement on origin on the invoice.

The role of the customs agency

A chain involving the UK is an area where it is easy to make a costly mistake: the wrong assumption that "it's triangulation after all", missing proof of export within the deadline, an undetermined importer of record, or non-compliant proof of origin. A customs agency sorts this out operationally: it classifies the individual legs, establishes who clears the goods and where, assembles the documents, and looks after the proofs of export that entitle you to the 0% rate. Easy Clearance handles export and import clearances on the PL–UK route and helps you put together the documentation for a chain involving the United Kingdom.

What follows from the current rules

The EU simplified procedure in a triangular transaction (WTT) requires three taxable persons registered for intra-Community transactions in three different EU Member States (Articles 135–138 of the Polish VAT Act, Article 141 of Directive 2006/112/EC). Because since 1 January 2021 the United Kingdom (GB) has been a third country, an entity with a GB number cannot take part in this procedure — a chain involving it becomes export and import with customs clearance on both sides, and the importer is determined by the Incoterms. Northern Ireland (XI number) remains within the EU VAT area for goods and can in principle take part in triangulation, but the practical acceptance of the XI prefix varies and requires verification. In every chain involving the UK the documents are key: the invoice, proof of export (IE599), the import declaration, EORI (GB and EU) and proof of origin where the TCA preference applies. This article reflects the legal position as at 2026-06-13. Contact a customs agency or tax adviser before taking any action.

FAQ — frequently asked questions

Can the United Kingdom be a party to an EU triangular transaction?

No. The simplified WTT procedure requires three taxable persons registered for intra-Community transactions in three different EU Member States (Articles 135–138 of the Polish VAT Act, Article 141 of Directive 2006/112/EC). The United Kingdom (GB) has been a third country since 1 January 2021, so a GB VAT number does not qualify for this procedure.

What replaces triangulation when a UK company is in the chain?

A chain involving GB breaks down into export and import with customs clearance on both sides. The EU–UK leg is an export (0% rate once proof of export is obtained) and an import (with duty and import VAT). Who is the importer and who clears the goods depends on the Incoterms (e.g. DAP — the buyer, DDP — the seller).

Can Northern Ireland (XI number) take part in triangulation?

In principle yes — for trade in goods Northern Ireland remains within the EU VAT area (Windsor Framework), and businesses use the XI number visible in VIES. In practice, acceptance of the XI prefix for triangulation purposes varies between EU Member States, so it is worth confirming each such transaction with a local tax adviser.

What documents are needed in a chain involving the UK?

A commercial invoice with the Incoterms, an export declaration and proof of export (IE599 on the EU side; export from the UK via CDS), an import declaration in the country of importation, EORI numbers (GB and EU) and — where the TCA tariff preference applies — proof of origin in the form of a statement on origin on the invoice.

What is the simplified procedure in a triangular transaction?

It is a settlement in which, with three taxable persons from three different EU Member States and direct transport of the goods from the first to the last, the VAT on the supply to the final customer is accounted for by that final customer. As a result the intermediary does not have to register for VAT in the country of destination. The intermediary's invoice must include the required annotations (Article 136 of the Polish VAT Act).

Official sources

• Ustawa z 11 marca 2004 r. o podatku od towarów i usług (art. 135–138 — WTT i procedura uproszczona) — ISAP — ISAP / Sejm RP
• Dyrektywa Rady 2006/112/WE (art. 141 — procedura uproszczona; art. 36a — transakcje łańcuchowe) — EUR-Lex — EUR-Lex
• VAT and trade with Northern Ireland — gov.uk HMRC — GOV.UK
• Exports and dispatches (proof of export, 0% rate) — VAT Notice 703 — gov.uk — GOV.UK
• Get proof of origin for your goods (TCA, statement on origin) — gov.uk — GOV.UK