What to put on an invoice in the UK, and how to get it paid

A UK invoice must show a unique invoice number, your name, address and contact details, your client's name and address, a clear description of what you're charging for, the date you did the work, the invoice date, the amounts, any VAT and the total owed. If you're a sole trader using a business name, it must also show your own name and an address where legal documents can be delivered to you. That's the list in gov.uk's guide to what invoices must include.

What a sole trader's invoice must show

Gov.uk gives nine items:

1. A unique identification number. One per invoice, never reused.
2. Your name, address and contact details.
3. Your client's name and address. For a business client, its company name.
4. A clear description of what you're charging for. "Homepage design, two rounds of revisions" says far more than "Design work".
5. The supply date: when you did the work. For a longer job, the period it covers.
6. The invoice date. It's a separate item from the supply date, even when they fall on the same day.
7. The amounts being charged.
8. VAT, if you're registered for it.
9. The total amount owed.

Sole traders add two more. The invoice must show your own name alongside any business name you trade under, so "Sam Patel trading as Northlight Studio" rather than "Northlight Studio" on its own. And if you use a business name, it must give an address where legal documents can be delivered to you. That duty comes from section 1202 of the Companies Act 2006, and if your business is based in the UK the address has to be a UK one.

The guide's overview page adds one more: an invoice must say when the customer has to pay you. So give it a due date, written as a date.

Strictly, the law only obliges you to issue an invoice when you and your client are both VAT registered. In practice clients expect one, and you need a record of every sale for your Self Assessment anyway, so send one every time.

What doesn't need to go on it, and what helps

Your Unique Taxpayer Reference and your National Insurance number aren't on gov.uk's list. A client doesn't need either to pay you, so keep them off.

Three things aren't legal requirements but decide how quickly the money arrives:

• How to pay you: your account name, sort code and account number, or a link to pay by card.
• Your payment terms in words, such as "Payment due within 14 days of the invoice date", next to the due date.
• The client's purchase order number or reference, if they use one. Without it, an invoice can sit unprocessed.

What changes for a limited company or VAT registration

If you trade as a limited company

The invoice comes from the company, not from you. It must carry the company's full registered name exactly as it appears on the certificate of incorporation, under regulation 24 of the trading disclosure rules. If you name any directors on it, you must name all of them. Payment goes to the company's bank account, not your personal one.

Your company number, registered office and where the company is registered must appear on business letters, order forms and your website, according to gov.uk. Invoices aren't on that list, but adding the number and office costs nothing and makes the invoice easy to check.

If you're VAT registered

Once HMRC registers you, your VAT registration number goes on every invoice you raise. You can't include VAT on an invoice until you have that number.

When you sell standard or reduced rated work to another VAT registered business, you must give them a VAT invoice, normally within 30 days of the tax point. It adds the tax point, the VAT rate and amount before VAT for each line, and the total VAT in sterling. Section 16 of HMRC's VAT guide has the full list.

Not registered? Then there's no VAT line and no VAT number anywhere on the invoice. Our guide to invoicing when you're not VAT registered covers the wording. If your turnover is getting close to the £90,000 VAT threshold, read VAT registration for freelancers.

How to number your invoices

For an ordinary invoice, gov.uk asks for one thing: a unique identification number. For a VAT invoice, HMRC is more specific. It wants "a sequential number based on one or more series which uniquely identifies the document" (VAT Notice 700, paragraph 16.3).

"One or more series" is the useful part. You can run separate sequences, as long as each number is only ever used once:

• One running sequence: 001, 002, 003.
• A year in front: 2026-001, 2026-002, then 2027-001. The year keeps each number unique, so starting again at 001 in January is fine.
• A prefix per client: ACME-001, ACME-002, then KELSO-001 for the next client. Handy when a client wants their own invoices in order.

Pick one scheme and keep it. Gov.uk's rule is that every number is unique, so never reuse one. One more habit is good practice rather than a written rule: never delete an invoice you've sent. If it's wrong, issue a credit note that cancels it, then a new invoice with the next number.

If you're VAT registered, the second habit becomes a rule. You must keep copies of every sales invoice you issue, even ones you cancel or produce by mistake.

When the invoice is due

If you don't agree a payment date, the customer must pay within 30 days of getting your invoice or the work, according to gov.uk. Agree a shorter term in your contract before you start, then print the actual due date on the invoice. A term that first appears on the invoice was never agreed, which is why it belongs in the contract. Our guide to invoice payment terms helps you pick one.

Habits that get invoices paid

Send it the day you deliver. Payment terms count from the invoice, so a week's delay in sending it is a week's delay in being paid. Before the first invoice to a new client, ask who approves it and which email address it goes to. If they pay suppliers on a set day each month, ask which day and get the invoice in before it. On a longer project, invoice in stages (our guide on asking for a deposit covers how).

Make paying easy. A card payment link lets a client pay from the invoice instead of setting you up as a new payee. Keep your bank details the same on every invoice, and tell new clients they'll never change by email. If a message ever says they have, the client should phone you on a number they already have before paying.

Add the late payment line for business clients. When your client is a business, the Late Payment of Commercial Debts (Interest) Act 1998 lets you claim statutory interest of 8% a year over the Bank of England base rate. You can add a fixed sum for the cost of recovery too, set by the size of the debt. Saying so on the invoice puts the client on notice before anything is late. It doesn't cover private individuals. Our interest calculator works out the sum, and late payments: your rights covers claiming it.

Remind before it's late. A short note a few days before the due date catches the invoice sitting in the wrong inbox. Follow up on the due date, then again a week later. Our chasing emails have the wording for each step.

The bottom line

Put gov.uk's nine items and a due date on every invoice, with your own name if you trade under a business name and a number you've never used before. Add how to pay you, then send it the day the work is done. A company or VAT registration adds a few fixed lines: set them up once and they're on every invoice after.