If you're self-employed, an invoice is how you ask to be paid and how you prove what you earned. It doesn't need to be fancy, but it does need the right details. Here's how to do it properly.
What a UK invoice must include
GOV.UK lists what an invoice must show:
- a unique invoice number
- your business name, address and contact details
- the customer's name and address
- a clear description of what you're charging for
- the date the work was done (the supply date)
- the date of the invoice
- the amounts charged, any VAT, and the total owed
As a sole trader, you must also show your own name and any business name you trade under. If you use a business name, you need to give an address where legal documents can be sent.
Numbering your invoices
Each invoice needs its own number, and the numbers should run in order. A simple system is best: INV-0001, INV-0002 and so on. Don't restart at 1 each year unless you add the year, such as 2026-001. Never reuse a number, even if you cancel an invoice.
Our invoice generator remembers the last number you used on your device and suggests the next one.
Describe the work properly
"Work carried out: £450" is the kind of line that gets queried. Break the job into parts the customer recognises: labour, materials, call-out, waste removal. Use the quantity column for hours or days. Customers pay clear invoices faster, because there's nothing to question.
Payment terms
Say when you want to be paid. Most tradespeople ask for payment within 7 or 14 days, or on receipt for small jobs. Put the due date on the invoice, not just "14 days", because a date is harder to ignore.
For business customers, if no payment date was agreed, the law treats payment as late 30 days after the customer gets the invoice or after you've done the work, whichever is later.
Include your bank details and ask the customer to use the invoice number as the reference. It makes matching payments in your banking app much easier.
Should you add VAT?
Only if you're VAT-registered. You must register once your taxable turnover goes over £90,000 in a rolling 12 months, and you can register voluntarily below that. If you're not registered, don't add VAT and don't show a VAT line. Read our guide: Do I need to register for VAT?
If you work for contractors in construction, you may need a CIS invoice instead. It works out the deduction your contractor makes.
Sending the invoice
Send it as soon as the job is done. Every day you wait is a day later you get paid. A PDF by email or WhatsApp is fine for most customers. Keep the file name sensible, such as "INV-0042 - Mrs Smith.pdf", so you can find it later.
When the customer pays, you can send a receipt to confirm it. It's a nice touch, and useful for customers who pay in cash.
If you're not paid on time
Send a polite reminder a few days after the due date. Most late payers simply forgot. Our guide to chasing an unpaid invoice covers what to do next.
Keeping records
HMRC expects you to keep records of your business income and expenses. GOV.UK says you must keep your records for at least five years after the 31 January submission deadline of the relevant tax year. For example, records for 2025 to 2026, filed by 31 January 2027, must be kept until at least the end of January 2032.
The easiest way is a folder for each tax year (6 April to 5 April) with every invoice and receipt PDF in it.
Ready to make one? Free, no sign-up, and your details stay on your device.
Frequently asked questions
Do I need a business bank account to invoice?
Sole traders don't legally need a separate business account, but many find it makes record keeping much easier.
Can I invoice before the job is finished?
Yes. On longer jobs it's common to invoice in stages, such as a deposit, stage payments and a final balance. Say which stage each invoice covers.
What if I make a mistake on an invoice I've sent?
Don't edit and resend it under the same number. Explain to the customer, and issue a corrected invoice with a note about what changed.
This guide is general information, not tax or legal advice. Rules change, so check GOV.UK for the latest position.