How to write your first invoice (UK)

Your first invoice is a rite of passage, and easier than it looks. Here's what a UK invoice actually needs, without the accounting-textbook fog.

What must be on it

• The word "Invoice" and a unique invoice number (sequential: INV-0001, INV-0002. Don't reuse or skip randomly; HMRC likes sequences).
• Your details: trading name and address. Limited company? Use the registered name; sole trader? your own name and business name if you have one.
• The client's name and address.
• Issue date, and ideally a due date.
• What you did, itemised: description, quantity, unit price, line total.
• The total owed: and if you're VAT-registered, the net amount, the VAT amount, and your VAT number.

The VAT question, simply

• Not VAT-registered (under the registration threshold and haven't opted in)? Don't charge VAT, don't mention VAT rates, just your totals. You cannot charge VAT without being registered.
• VAT-registered? Add VAT (usually 20%) on top of your net prices, show net / VAT / gross separately, and display your VAT number.

Payment terms that actually get you paid

State them explicitly: "Payment within 14 days by bank transfer" beats silence. Include your sort code and account number. For new clients or bigger jobs, consider a deposit up front. You set that expectation at the quote stage, not the invoice.

Late payers? UK law entitles you to statutory interest and a fixed fee on overdue commercial invoices, a polite reminder that mentions this tends to focus minds.

Common first-timer mistakes

1. Arithmetic errors, the classic. Line totals that don't sum, VAT calculated on the wrong base.
2. Missing invoice numbers. Makes your own bookkeeping miserable within months.
3. Charging VAT without being registered, genuinely not allowed.
4. No due date. "whenever" is what you'll get.

The fast way

Vizivo's Invoice Generator does the arithmetic precisely, handles the VAT presentation, carries your address and VAT number automatically, and exports a branded PDF. Your first invoice takes about a minute.