How to invoice in United Kingdom: what a compliant invoice must show

What every invoice must show

Whatever your trade, these fields are the minimum:

• The word Invoice (or Tax Invoice where you charge VAT) and a unique sequential number.
• Issue date and, for services, the date or period of supply.
• Your business name, address and VAT number; your registration number if you have one.
• The client's name and address, and their VAT number when they are a registered business.
• One line per item or service: description, quantity, unit price and line total in GBP.
• Subtotal, VAT rate and amount (or a statement that none was charged), and the total due.
• Payment terms, due date and bank details.

In United Kingdom specifically:

• VAT invoices must show the VAT number, the rate per line, the VAT amount and the tax point (time of supply).
• Simplified invoices are allowed for sales under £250.

Numbering and dates

Numbers must run in sequence with no gaps or repeats; HM Revenue and Customs (HMRC) checks for both. Use a prefix per year or series if it helps (2026-001), but never reissue a number. The issue date fixes the tax period the sale falls into, so date the invoice when you send it, not when the work started.

Showing VAT

Only registered businesses charge VAT. If you are registered, show the rate and the amount as separate lines; if you are not, do not show a VAT line and say so on the document. Charging VAT without registration is an offence in most countries, and clients' accountants will spot it.

Electronic invoicing in United Kingdom

No mandatory B2B e-invoicing yet; HMRC has consulted on it. PDFs are fine, but VAT records must be kept digitally under Making Tax Digital.

Many countries now require invoices to be issued through, or reported to, an official electronic system. Where United Kingdom does, the PDF you make here is a working document for quotes, proformas and internal records, and the fiscal invoice comes from the official system. Where it does not, an emailed PDF is a valid invoice.

Getting paid

State the due date, not just the terms. Put the bank details on the invoice and ask for the invoice number as the payment reference. Send the PDF on the day the work finishes; late invoices are paid late. A proforma up front is the cleanest way to ask for a deposit.

Fixing a mistake

Never edit or delete an invoice you have sent. Issue a credit note that references the original number, states the reason and reverses the same VAT, then issue a new invoice if needed. The United Kingdom credit note generator does this.