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Export Documents

The commercial invoice is the most important document in an international shipment. Customs authorities on both sides of the transaction use it to assess duty, verify the value of the goods, and determine whether the shipment can be cleared. A mistake on the invoice can hold your parcel at the border, trigger a formal inspection, or cause your EU buyer to pay full duty when they should have paid zero. These are the errors that appear most often — and how to avoid them.

1. Vague or Generic Product Descriptions

Writing "gift", "sample", "parts", "merchandise", or "clothing" in the goods description is one of the most common and most consequential mistakes on a commercial invoice. Customs officials need to know exactly what the goods are in order to classify them, assess the correct duty rate, and determine whether any import controls apply.

A correct description gives enough information to identify the goods without ambiguity: "handmade beeswax pillar candles, unscented, 20 cm" is correct. "Candles" is marginal. "Gifts" will likely trigger a manual inspection or refusal. See the full commercial invoice guide for the complete list of required description fields.

2. Wrong or Missing HS Code

Every line item on a commercial invoice should carry an HS (Harmonised System) commodity code — ideally the full 10-digit commodity code, but at minimum the 6-digit HS code that is internationally recognised. A wrong HS code is not a minor administrative error: it affects the duty rate applied by destination customs, determines whether any prohibitions or restrictions apply, and triggers manual review when the code doesn't match the description.

Missing HS codes are increasingly flagged as a risk indicator by major couriers. Shipments without commodity codes are more likely to be held for inspection. Include the correct code for every line item, every time.

3. Undervaluing the Goods

Declaring goods at a lower value than the actual transaction price — to reduce the duty and VAT liability in the destination country — is customs fraud. Both HMRC and destination customs authorities use risk-profiling systems and benchmark prices to identify declarations that look too low. For common categories like clothing from China or electronics from the US, reference price databases exist and declarations that fall significantly below them are flagged automatically.

If you're found to have undervalued goods, the consequences are disproportionate to any short-term saving: retrospective duty and VAT demands, civil penalties, potential criminal referral, and reputational damage with customs authorities. Declare the actual transaction value — always.

4. Wrong Country of Origin

The country of origin on your commercial invoice is not the country you're shipping from — it's the country where the goods were manufactured or where they last underwent substantial transformation. This distinction matters enormously for duty purposes. Under the UK-EU Trade and Cooperation Agreement, goods that originate in the UK qualify for 0% duty. Goods that originate in China and are merely reshipped from the UK do not.

Claiming UK origin for goods that don't meet the TCA's rules of origin is a false declaration. Your EU buyer's customs authority may audit the claim years later. Understand how rules of origin work before you certify origin on your invoice.

5. Missing or Incorrect Incoterms

Incoterms (International Commercial Terms) define the split of costs, risks, and responsibilities between buyer and seller in an international transaction. They directly affect customs valuation: some Incoterms (like CIF — Cost, Insurance, Freight) include shipping and insurance in the customs value; others (like FOB — Free On Board) do not.

Omitting Incoterms from your invoice leaves both parties and customs without a clear basis for valuation. Specifying the wrong Incoterm can mean your buyer pays duty on the wrong customs value. The most common terms for small business exports are DAP (Delivered At Place) and DDP (Delivered Duty Paid) — confirm which applies to each transaction and state it explicitly on the invoice.

6. Invoice in the Wrong Currency

The currency on the commercial invoice must match the currency of the actual transaction. If you invoiced your buyer in euros, the invoice must state euros. If you invoiced in pounds sterling, state GBP. Destination customs authorities convert the declared value to local currency for duty assessment — using the rate for the currency declared. Stating the wrong currency creates a discrepancy between your invoice and your buyer's payment records that can raise questions during a compliance check.

7. Missing or Duplicated Invoice Numbers

Every commercial invoice must carry a unique invoice number. This number is the primary reference used by couriers, customs agents, and your buyer to track the shipment and match it to the customs declaration. A missing invoice number means the shipment cannot be properly referenced. A duplicated number — using the same number on two invoices — causes reconciliation errors in your buyer's accounts, creates problems for HMRC record-keeping, and can flag your account for a compliance review.

Use a consistent, sequential numbering system and never reuse a number, even for a reissued invoice. Retain all invoices for at least six years if you're VAT-registered.

8. Inconsistency Between Invoice and Packing List

Your commercial invoice and packing list are produced for the same shipment, but many exporters produce them separately — which introduces the risk that the quantity, description, or weight on one doesn't match the other. Customs compare these documents as a matter of routine. If the invoice says 50 units and the packing list says 48 units, the shipment will be held until the discrepancy is explained.

The safest approach is to generate both documents from a single data entry at the same time, so inconsistency is structurally impossible. That's exactly how ClearDocs handles the document pair — one entry produces both the invoice and packing list simultaneously, with consistent data throughout.

The Practical Fix

Most commercial invoice mistakes are not errors of bad intent — they're errors of process. An exporter using a Word template they've adapted over time, filling it in under pressure before a collection deadline, will eventually make one of the errors above. The fix is to use a structured tool that enforces the required fields, pre-populates the correct format, and prevents the invoice and packing list from diverging.

ClearDocs generates commercial invoices with all required fields pre-structured — goods description, HS code, country of origin, Incoterms, currency, invoice number — and produces the matching packing list from the same data entry. The fields that cause the most customs problems are the ones the form requires you to complete before the document will generate.