What an invoice must include (and how to make one for free in a minute)

An invoice is more than a piece of paper with a number on it: it is the record of a sale for you, for your client and for the tax authority. If something is missing, your client may not be able to reclaim the VAT and you may have to reissue it. The good news is that the list is short and always the same.

What every invoice needs

Whatever country you work in, a proper invoice includes:

1. A unique invoice number that follows on from the previous one (for example INV-2026-001, INV-2026-002…).
2. The invoice date, and the date of the sale or service if it is different.
3. Your details: your name or company name and address.
4. Your client's details: their name or company name and address.
5. A description of what you are charging for: the quantity and the unit price of each item.
6. The total amount, and how and when you expect to be paid.

Extra details on a UK VAT invoice

If you are VAT-registered in the UK, HMRC also asks for:

• your VAT registration number;
• the time of supply (tax point), if it differs from the invoice date;
• for each item, the unit price excluding VAT, the VAT rate and the amount;
• the total excluding VAT, the total VAT and the total payable.

The standard rate is 20 %, the reduced rate 5 % and some goods are zero-rated. Here is how the figures add up:

Item	Amount
Net amount	£1,000.00
VAT (20 %)	£200.00
Total	£1,200.00

For sales of £250 or less including VAT you can issue a simplified invoice, with fewer details: you can leave out the client's address and show the total including VAT.

Common mistakes

• Skipping or reusing numbers. If you cancel an invoice, don't delete it: issue a credit note.
• Removing VAT by taking 20 % off the total. From £120 including VAT the net amount is £100 (120 ÷ 1.2), not £96. When in doubt, use the VAT calculator.
• Vague descriptions such as "services". The more specific, the fewer questions later.
• Forgetting the payment terms. Say when payment is due and how (bank details, payment link).
• Sending it late. The sooner you invoice, the sooner you get paid.

How long should you keep invoices?

In the UK, businesses must keep VAT records for at least six years. Store them as PDF files with a backup. Other countries have their own periods, usually between four and ten years, so check the rules where you are.

These are general guidelines. If you are unsure about your own case, ask your accountant.

Make your invoice for free

With the free invoice generator you fill in a form with all these fields, see the invoice as you type (with the total in words if you like) and save it as a PDF. No sign-up, and nothing you type leaves your browser.

And if you invoice every month, Documentemplate turns it into a template: VAT as a constant, totals worked out for you and every new invoice ready in seconds.