Commercial Invoice for Exports to the UK — Mandatory Fields, KSeF and 0% VAT

Exporting goods from Poland to the United Kingdom requires not only a customs declaration, but also a correctly issued commercial invoice. Errors in the document — a missing HS code, the wrong currency, or no EORI number — can hold up the goods at the border or cost the company the right to the 0% VAT rate. This article is for exporters, sales teams and accounting departments handling PL→UK transactions.

What is a commercial invoice and how does it differ from a VAT invoice?

The commercial invoice is the basic document accompanying an export shipment — required by the customs authority on both the PL side (AES/PUESC export declaration) and the UK side (CDS import clearance). It does not replace a VAT invoice, but exporters often combine both documents — provided it contains all the required fields.

After Brexit, the UK is a third country: every shipment from Poland to England, Scotland or Wales is subject to the full export (PL) and import (UK) procedure.

Mandatory fields on a PL→UK commercial invoice

The HS code — a key field

The HS code is the basis on which HMRC calculates duty. Poland uses the 8-digit CN, while the UK has its own 10-digit tariff (the UK Global Tariff). The correct code allows the importer to lodge a correct CDS declaration. Check the code: UK Trade Tariff — Find a commodity.

EORI — both numbers current

The exporter must hold a PL EORI number (KAS, free, applied for via PUESC). The buyer in the UK needs a GB EORI number (HMRC, free, a few days to obtain). Without a GB EORI number, the importer cannot lodge a CDS declaration — the goods will be held.

Incoterms — the effect on customs value

Incoterms 2020 determine who bears the costs and risk. Customs value in the UK is based on the transaction value plus the cost of transport/insurance to the GB port. Enter the full term and place, e.g. CIF Felixstowe or DAP London.

0% VAT on exports — documentary conditions

Exports from Poland are subject to a 0% VAT rate (Article 41(4) of the Polish VAT Act). The condition is holding a document confirming the goods left the EU before the deadline for filing the VAT return.

The IE599 message (CC599C)

IE599 is the electronic message confirming that the goods have left the EU customs territory — an XML document stamped by the system, giving legal certainty for the 0% rate. It is available in the exporter's PUESC account once the export is completed.

IE529 — a temporary document

IE529 confirms that the export procedure has started (the declaration has been accepted). It can serve as a temporary document: if IE599 is still missing by the 25th day of the month following dispatch, but IE529 exists (direct export), the export can be deferred by one month. If neither is available, the export is reported as a domestic sale and corrected once the document is obtained.

KSeF and export invoices — current status (May 2026)

The National e-Invoice System (KSeF) is a system for issuing structured e-invoices through the Ministry of Finance platform.

Important: These dates come from the Act (Journal of Laws item 852). KSeF regulations have been amended repeatedly — always check the current status at ksef.podatki.gov.pl.

The KSeF obligation covers invoices issued by Polish VAT payers, including export invoices (where they also serve as a VAT invoice). An invoice from KSeF is given a unique KSeF number, which can be entered in the customs declaration's references; the version used for clearance (a PDF for the agent/importer) is a printout/export from KSeF carrying that number or a QR code.

Common mistakes

1. Missing HS code or incorrect classification — the goods are held, the UK declaration has to be corrected.
2. No buyer (GB) EORI number — the importer cannot lodge a CDS declaration; storage costs are incurred.
3. Undervalued goods / no Incoterms — HMRC may challenge the customs value.
4. Mismatch between the invoice description and the EX declaration — risk of the 0% VAT rate being refused.
5. No IE599 within the deadline — the export is reported as a domestic sale and the return has to be corrected.

Frequently Asked Questions (FAQ)

Does the invoice have to be in English? There is no absolute requirement on the PL side, but for UK clearance, documents in English or with a translation are expected — in practice, virtually all PL→UK invoices are in English or bilingual.

Do I need a Polish EORI number to export to the UK? Yes. Without a PL EORI number you cannot lodge an export declaration in PUESC. The number is free.

What about shipping by courier (DHL, DPD, FedEx)? The courier often lodges the EX declaration, but you must provide a complete invoice — errors on the invoice carry through to the declaration.

Does the £135 threshold apply to exports to the UK? The £135 threshold relates to imports into the UK (UK VAT collected at the point of sale). It does not change the export obligations on the PL side.

Do I need a separate TCA agreement to benefit from 0% duty? No — zero duty for goods meeting the TCA rules of origin is available automatically. You must document Polish/EU origin (a statement on the invoice or an EUR.1 certificate).

How we can help

At Agencja Celna (agencjacelna.uk) we handle PL↔UK export and import: preparing and checking commercial invoices, EX export declarations in PUESC, PL and GB EORI numbers, tariff classification (HS codes), and UK import clearance (CDS). Get in touch before your first shipment: agencjacelna.uk

Sources

• KSeF — legal basis and deadlines (ksef.podatki.gov.pl)
• UK Trade Tariff — Find a commodity
• EORI GB — registration (gov.uk/eori)
• PUESC