Eleven mandatory fields under Regulation 14 of the VAT Regulations 1995. A single missing or incorrect field can block the customer from reclaiming input VAT.

The 11 mandatory fields (Reg 14)

All eleven required on a full UK VAT invoice. The simplified-invoice rules at £250 drop several of these.

Unique sequential invoice number.
Invoice date.
Time of supply (the tax point) if different from the invoice date.
Supplier's name, address, and VAT registration number.
Customer's name and address.
Description sufficient to identify the goods or services.
Per line: quantity, unit price, VAT rate, and amount excluding VAT.
Rate of any cash discount.
Total amount excluding VAT.
Total VAT payable in sterling.
Total amount including VAT.

What about the £250 simplified VAT invoice?

For retail-style sales of £250 or less including VAT, the simplified rules drop the customer name and address and skip the VAT breakdown: just the VAT-inclusive total and the rate(s) applied. Simplified invoices cannot be used for B2B sales over £250. For retail sales above £250 to a non-business customer, the modified format allows VAT-inclusive line items provided the rate is shown clearly and the customer agrees.

When does the reverse charge apply?

Domestic CIS construction services and certain cross-border B2B supplies. The invoice shows £0 VAT plus a clear statement: 'Reverse charge: customer to pay VAT to HMRC' or 'Reverse charge: VAT Act 1994 section 55A applies'. Forgetting this notice is one of the most common ways CIS sub-contractors fall foul of HMRC. The invoice/receipt/quotation taxonomy covers when each document fits in the trade sequence.

How long do I keep VAT invoices?

Six years minimum. From April 2026, sole traders and landlords with combined business and property income above £50,000 must keep records in Making Tax Digital-compatible software; the threshold falls to £30,000 from April 2027 and £20,000 from April 2028.

How to Issue a Valid UK VAT Invoice

Step-by-step: assign a sequential invoice number, populate the 11 mandatory fields under Regulation 14 of the VAT Regulations 1995, handle the simplified-invoice and reverse-charge exceptions, and keep records for the 6-year retention rule.

Assign a unique sequential invoice number

Every VAT invoice needs a unique number drawn from a sequential series. Most accounting software handles this automatically; if you issue manually, never skip or reuse a number — gaps and duplicates are common audit flags.

Populate the 11 mandatory fields

Under Regulation 14: invoice number; invoice date; tax point if different; supplier name, address, and VAT number; customer name and address; supply description; per-line quantity / unit price / VAT rate / net amount; cash-discount rate; total net; total VAT in sterling; total gross. A single missing or incorrect field can block the customer from reclaiming input VAT.

Use a simplified invoice for retail under £250

For retail-style sales of £250 or less including VAT, drop the customer name and address and skip the VAT breakdown — show only the gross total and applicable rate(s). Simplified invoices cannot be used for B2B sales over £250.

Apply the reverse charge where required

For domestic CIS construction services and certain cross-border B2B supplies, show £0 VAT and state clearly: "Reverse charge: customer to pay VAT to HMRC" or "Reverse charge: VAT Act 1994 section 55A applies". Forgetting this notice is one of the most common ways CIS sub-contractors fall foul of HMRC.

Retain records for 6 years

Keep copies of every sales and purchase invoice for at least 6 years. From April 2026, sole traders and landlords above the £50,000 income threshold must keep records in MTD-compatible software (threshold falls to £30,000 in April 2027 and £20,000 in April 2028).

What Makes a UK VAT Invoice Valid?