Commercial invoice for UK imports – mandatory fields and checklist [15-point guide]

The commercial invoice is the single most important document in every UK customs clearance. It is the basis on which the customs agent and HMRC establish the customs value of the goods, calculate the applicable duty, and determine the import VAT. Without a correctly completed commercial invoice no shipment will cross the border without problems — and that is meant literally: an incorrect invoice means goods held up, additional demurrage charges at the customs warehouse, and delays that can cost far more in the supply chain than simply correcting the document. In practice we see hundreds of invoices every year that are rejected or require clarification — and almost always the problem lies in the same few fields. This article is a practical 15-point checklist of mandatory elements of a commercial invoice for UK imports, supplemented by the most common mistakes made by exporters from Poland and the EU, the differences between B2B and B2C invoices, and guidance on purchases from private individuals. Read it before sending your first consignment to Great Britain — it will save you both nerves and money.

Why the commercial invoice matters so much in UK customs clearance

Since Brexit (from 1 January 2021) the United Kingdom has been a separate customs territory. Every item crossing the border — both imports into the UK and exports from the UK — requires full customs documentation in line with HMRC requirements. The commercial invoice is document number one, because it is the basis for:

• the customs agent completing the import declaration (Import Declaration, SAD/C88),
• HMRC calculating the customs value according to WTO rules,
• establishing the HS code of the goods and the applicable duty rate,
• verifying the country of origin and any tariff preferences (e.g. 0% duty under the TCA),
• charging import VAT (Import VAT, normally 20%).

The commercial invoice must be issued by the seller/exporter to the buyer/importer and should accompany the shipment in paper or electronic form. HMRC may request the original as part of a post-import audit for up to 4 years after clearance.

Full requirements for preparing to import goods from the EU into the United Kingdom are set out on gov.uk.

15 mandatory fields on a commercial invoice for UK imports

The table below lists every field that must appear on a commercial invoice submitted for customs clearance in the UK.

No.	Field	Requirement	Example
1	Invoice date	Mandatory	15.04.2026
2	Unique invoice number	Mandatory	INV-2026-0412
3	Seller (exporter) details	Full name, address, country	Kowalski Export Sp. z o.o., ul. Przemysłowa 5, 00-001 Warsaw, Poland
4	Exporter EORI number	Mandatory for exports from the EU	PL1234567890
5	Buyer (importer) details	Full name, address, country	UK Buyer Ltd, 10 Trade Street, London E1 6RF, UK
6	UK importer EORI number	Mandatory for imports into the UK	GB987654321000
7	Description of goods	Detailed — not a catalogue code	Upholstered office chairs, metal frame & fabric, 50 units
8	HS code (Commodity Code)	Minimum 6 digits; 10 digits recommended	9401.30.00.00
9	Country of origin	ISO 3166-2	PL (Poland)
10	Quantity and unit of measure	Mandatory	50 units / 500 kg
11	Unit price and total value	In a single currency	120 EUR/unit, total 6,000 EUR
12	Invoice currency	One currency throughout the document	EUR
13	Incoterms + place	Abbreviation + location	CIF Dover
14	Payment terms	Optional but recommended	30 days from invoice date
15	Exporter signature/stamp	Mandatory if a statement on origin is included	Signature + company stamp

Most common mistakes on commercial invoices for the UK

From experience, more than 60% of invoices requiring correction have one of the following problems:

Missing HS code (Commodity Code) This is the single most common error. Exporters from Poland enter their internal product code or ERP system code instead of the HS (Harmonized System) code. The HS code is international — you need to find it in the UK Global Tariff on gov.uk. Without an HS code the customs agent cannot properly classify the goods.

Vague or imprecise description of goods "Machine parts", "metal products", "foodstuffs" — such descriptions are insufficient. HMRC requires a detailed description: material, intended use, condition (new/used), dimensions, chemical composition (for foodstuffs). The more precise the description, the lower the risk of the shipment being held for physical inspection.

Different currencies on the invoice and the contract If the contract is in USD but the invoice is in EUR, HMRC may request an explanation of the exchange rate used to calculate the customs value. Always keep the currency consistent, or attach a note stating the exchange rate applied.

Missing EORI number Both the exporter (EU/PL) and the importer (UK) must have an EORI number. The UK importer format is GB followed by 12 digits. UK EORI registration is free and takes 3–5 working days.

Missing or incorrect Incoterm The Incoterm determines up to what point transport costs are included in the customs value (CIF vs FOB affects the duty and import VAT amount). CIF (Cost, Insurance and Freight) is the standard for UK imports.

Sample commercial invoice template for UK imports

Below is a simplified invoice layout that meets HMRC requirements:

COMMERCIAL INVOICE

Seller/Exporter:                         Buyer/Importer:
[Company name]                           [UK company name]
[Full address]                           [Full UK address]
[EORI: PL...]                            [EORI: GB...]
VAT EU: PL...

Invoice No.: INV-2026-XXXX              Date: DD.MM.YYYY
Purchase Order No.: PO-XXXX

GOODS DESCRIPTION:
+------------------------+------+--------+----------+----------+
| Description            | HS   | Country| Quantity | Value    |
|                        | Code | of     | (pcs/kg) | (EUR)    |
|                        |      | Origin |          |          |
+------------------------+------+--------+----------+----------+
| [Detailed description] | XXXX | PL     | XX pcs   | X,XXX.00 |
+------------------------+------+--------+----------+----------+

Total value: X,XXX.00 EUR
Incoterms: CIF Dover
Payment terms: 30 days

I hereby declare that the information contained in this invoice is true and accurate.
[Signature] [Date] [Stamp]

Differences between B2B and B2C commercial invoices

Invoices for individual consumers (B2C) have several important differences compared with commercial transactions (B2B):

B2C imports into the UK: - For consignments valued up to £135: VAT is collected by the seller at the point of sale (through an e-commerce platform or directly); no customs duty applies. - For consignments valued above £135: standard customs clearance as for B2B; import VAT and duty are collected at import. - The invoice must show the retail price paid by the consumer clearly.

The key practical difference: in B2B transactions the invoice shows the net wholesale value. In B2C it shows the retail price paid by the consumer. Undervaluation is a customs offence in both the UK and the EU.

How to produce an invoice when buying from a private individual

Purchasing goods from a private person (not a company) is increasingly common — particularly for used machinery, vehicles, and antiques. In such cases:

1. The private seller issues a pro forma invoice or a simple written confirmation of sale containing all required fields.
2. If the seller does not have an EORI, enter "N/A" or provide their personal details (full name, address).
3. Pay particular attention to the customs value: HMRC may challenge the declared value in private-individual purchases, especially if the price appears understated.
4. Attach proof of payment (bank transfer, receipt) as supporting documentation.
5. For vehicles — attach the title document (V5C or foreign equivalent).