10 Common Mistakes in EU–UK Customs Documentation and How to Avoid Them

Since Brexit, trade between the European Union and the United Kingdom requires full customs documentation. Errors in documents lead to delays, extra costs and, in extreme cases, penalties. Below are the 10 mistakes that recur most often.

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1. Wrong tariff classification

A wrong commodity code means the wrong duty rate and often the wrong requirements (bans, restrictions, checks). How to avoid it: check the code in the tariff (TARIC in the EU, UK Trade Tariff in the UK) and describe the goods according to their characteristics; see our article on the HS code. If in doubt, you can apply for a binding tariff decision (BTI in the EU, ATaR in the UK).

2. Incorrect customs value

An understated or incomplete value can be treated as an attempt to avoid duty. How to avoid it: declare the transaction value and include every price element that must be added; see how to calculate customs value.

3. Incomplete sender or recipient details

Documents must contain complete, consistent details of the parties, including EORI numbers where required. How to avoid it: compare the details on the invoice, transport document and declaration before dispatch. For the number itself, see the guide to the EORI number.

4. Missing supporting documents

A missing commercial invoice, packing list, transport document or goods-specific document (for example a certificate) can hold up a shipment. How to avoid it: prepare the full set before dispatch; the list is described in our article on international trade documentation.

5. Misunderstanding the rules of origin

A 0% rate in EU–UK trade is not automatic: the goods must meet the TCA rules of origin, and origin is shown by the exporter's statement on origin (with a REX number above EUR 6,000) or by the importer's knowledge. The EUR.1 certificate is not used in this trade, and buying goods in the UK does not make them UK-origin. How to avoid it: see UK–EU rules of origin.

6. Ignoring the destination country's rules

Each country has its own import requirements, for example for food, product conformity or controlled goods. How to avoid it: check the requirements with the authorities (GOV.UK, KAS) before the first delivery, or ask a customs agency.

7. Missing licences or permits

Some goods (for example dual-use and controlled goods) need a licence or permit to import or export. How to avoid it: check before placing the order and apply in good time; see dual-use goods.

8. Unclear or unsuitable Incoterms

Unclear delivery terms cause disputes over who is responsible for transport, clearance and charges. How to avoid it: choose a rule that fits the transaction, make sure both parties understand it and name a specific place; see Incoterms EXW, FCA, DAP.

9. Missing out on a duty refund

In certain situations (overpayment, defective goods, an authority's error) paid duty can be recovered, but the claim must be made on time. In the EU this is in principle 3 years from notification of the customs debt (Article 121 of the Union Customs Code); in the UK HMRC gives 3 years for overpayments (other limits apply, e.g. 1 year for rejected imports), see GOV.UK: claim a repayment of import duty and VAT. How to avoid it: check the ground for a refund and the deadline as soon as you spot the error.

10. Out-of-date knowledge of the rules

Customs and trade rules change; for example, from 1 July 2026 the customs duty relief for consignments up to EUR 150 was abolished (Council Regulation (EU) 2026/382). How to avoid it: use current notices from GOV.UK, KAS and the European Commission, or a customs agency that follows them.

Avoiding these mistakes takes accuracy and up-to-date knowledge. If you would like your documents checked before dispatch, get in touch.

Frequently asked questions