Guides / Commercial invoice mistakes · Updated 19 October 2026

Commercial invoice mistakes that delay UK customs clearance

A customs invoice does not need to be elaborate, but a handful of recurring errors on an otherwise ordinary commercial invoice are what actually stop a UK import declaration at the border. Here are the ones worth checking before you ship, and what official guidance says about each.

Why the invoice is the first thing that gets checked

Whoever files your import declaration – you, a forwarder or a customs agent – builds it from the figures on your commercial invoice. GOV.UK's step-by-step import guidance says you need to include the commodity code and the value of your goods on the declaration, and that the value "helps work out how much duty and VAT you'll need to pay." Those figures have to come from the invoice. If the invoice is incomplete, inconsistent, or does not match what is actually being shipped, the declaration built on it inherits the same problem, and that is usually where a query starts.

This guide does not repeat the full field-by-field invoice checklist (our guide on export paperwork already covers seller/buyer details, descriptions, and value for exports). Instead, it focuses on the specific mistakes that most often trigger a customs query, a hold, or a rejected declaration on the import side, with each one tied to official guidance.

Mistake 1: leaving off the Incoterm or delivery terms

HMRC's Customs Declaration Service (CDS) completion guide is explicit: a delivery terms code "must be provided for declarations using valuation method 1 (transaction value of imported goods)" – the method used for the vast majority of imports. The code has two parts: the Incoterm itself (for example FCA, DAP or DDP) and the location up to which it applies, ideally a UN/LOCODE.

Leaving the Incoterm off the invoice does not just create ambiguity about who pays for freight and insurance. HMRC's own guidance warns that where the delivery terms used require an addition or deduction to the price to arrive at the customs value, "the corresponding addition or deduction code must be declared... to prevent the declaration being rejected." Without a clear Incoterm on the invoice, whoever is valuing the goods is guessing which costs are already in the price and which still need to be added.

Mistake 2: a goods description too vague to classify

GOV.UK's import guidance says you must include the commodity code on your declaration, and that this code "will determine the rate of duty you need to pay and if you need an import licence." The commodity code comes from the UK Trade Tariff, and whoever looks it up needs enough detail in the goods description to pick the right one. "Parts," "accessories" or "samples" on an invoice line leaves that decision to guesswork, and a wrong code can mean the wrong duty rate, a missed licence requirement, or a query asking for more detail before clearance continues.

Mistake 3: no commodity code reference at all

Some invoices carry only a product name and no commodity code or tariff reference, which is workable but slower: the agent still has to classify from scratch with no steer from the seller. Where the invoice already states the commodity code the seller used on their own export paperwork, or at least a precise tariff description, it gives the importer's agent a starting point to confirm rather than invent – and a mismatch between the exporter's code and the UK code is worth catching before the declaration is filed, not after.

Mistake 4: invoice and line totals that do not add up in the stated currency

HMRC's CDS valuation guidance requires that the currency declared for the total invoiced amount matches the currency used for the item price, and that the two figures are internally consistent: the total "must always be the same as the currency code" used for the item amount, and the invoice total "must correspond to the sum of the item price/amount for all items." An invoice that mixes currencies between a header total and line items, or where the lines do not sum to the stated total, forces whoever is declaring the goods to stop and reconcile it before they can proceed. The same guidance notes that if a proforma value is later replaced by a different final invoice figure, the declarant has to go back and request a post-clearance adjustment – extra work that a consistent invoice avoids from the start.

Mistake 5: no EORI number, or the wrong one

GOV.UK is direct about this: to import goods into England, Wales or Scotland you need an EORI number that starts with GB, and an EORI without that prefix means a new one is needed. An EORI number is also required to use the Customs Declaration Service itself. An invoice that omits the importer's EORI, or carries an old non-GB-prefixed number, does not stop the shipment moving, but it stops the declaration: GOV.UK is clear that you need an EORI number to make customs declarations at all, so this is typically the first thing an agent asks for if it is missing from the paperwork.

Mistake 6: a price that does not reflect what was actually paid

Most imports are valued under what HMRC calls Method 1, the transaction value: officially, "the price paid or payable by the buyer to the seller for the goods when sold for import to the UK," including any payment that is a condition of the sale. HMRC's guidance sets conditions for when Method 1 can be used – for example, where buyer and seller are related, the importer must be able to show the relationship did not affect the price, by comparison with prices between unrelated parties. If the invoice price cannot be supported as the real transaction value, Method 1 cannot be used and the importer has to fall back to one of HMRC's other five valuation methods, which generally means more paperwork and a slower clearance, not a lower bill.

None of this is about hiding value to reduce duty. HMRC can ask for evidence behind any declared value, and getting caught at a lower figure than the real transaction value risks far more delay and cost than simply invoicing correctly in the first place.

A quick pre-shipment check

Incoterm and named location are on the invoice, matching what was actually agreed
Goods description identifies what the item is, what it is made of and what it is for – not just a trade name
A commodity code or precise tariff description is included where the seller already knows it
Currency is consistent across every line and the invoice total, and the lines add up to that total
Both the exporter's and the importer's EORI numbers are shown
The invoice value is the real price paid or payable, including anything that is a condition of the sale

For how the customs value itself is actually calculated once the invoice is correct, see our guide to the six customs valuation methods. If you are not sure whether to file the declaration yourself, our guide on whether you need a customs broker walks through the trade-offs; a broker will typically request exactly the fields above before they will file on your behalf, as explained in our guide on how a broker files your import declaration in CDS.

Easy Clearance's guide on what a customs commercial invoice must show sets out the full field list for exporters sending goods to the UK, which is a useful companion to the mistakes covered here.

Related guides

Want the full invoice field list?

Easy Clearance is a UK–EU customs clearance agency handling import and export declarations, T1/T2 transit and UK–Poland removals. Its article sets out, field by field, what a compliant commercial invoice needs to show.

Read the invoice field guide

Sources

General information, not legal, tax or customs advice. Rules change; confirm current requirements on gov.uk or with a registered agent before you ship.