How to write an invoice (UK) — step by step

An invoice is your formal request for payment. Getting it right means you look professional, get paid faster, and keep records HMRC is happy with. Here’s how to write one, step by step.

1. Label it and number it

Put the word Invoice clearly at the top, and give it a unique invoice number. Numbers should be sequential with no gaps — see how to number invoices.

2. Add your details and your customer’s

Include:

• Your business name (and trading name if you use one) and address
• Your customer’s name and address
• A contact email or phone so queries are easy

If you trade as a limited company, you must also show your registered company name and number — see sole trader vs limited company.

3. Add the dates

Show the invoice date (when you’re issuing it) and the due date or payment terms, so there’s no doubt when payment is expected. See invoice payment terms explained.

4. Describe what you’re charging for

List each item or service on its own line with the quantity, the unit price and the line total. Clear descriptions mean fewer questions and faster payment.

5. Show the totals

Add the subtotal, then the total due. If you’re VAT registered, show the VAT rate and amount and your VAT number — follow what a VAT invoice must include. Not registered? Leave VAT off entirely; see invoicing without VAT.

6. Say how to pay

Add your bank details (or other payment method) and your payment terms. Make it as easy as possible to pay you on time.

Let the generator do it

The free invoice generator builds all of this for you — fill in your details, add your lines, and download a clean PDF. Nothing leaves your browser.