Key takeaways
- Agree the rate and the payment terms before the work starts.
- Invoice the day you deliver — fresher work gets paid faster.
- Set an explicit due date, not just “Net 30”, and make paying easy.
- Add VAT only if you are VAT-registered.
- Have a follow-up plan before you need one.
Agree the terms before you start
Confirm the rate — hourly or fixed — and the payment terms in writing before the work begins. Even a short email confirmation is enough. Nearly every invoice dispute traces back to a term that was never actually agreed.
Track the work or the deliverables
If you bill hourly, log your hours as you go rather than reconstructing them from memory at the end of the month. If you bill per project, note exactly what you are delivering. Your invoice lines come straight from this, and specifics are what stop a client querying a line.
Invoice the same day you finish
The fresher the work, the faster the payment. Sending the invoice the day you deliver is the single biggest habit to build — an invoice sent three weeks after the work is an invoice the client has to re-justify internally.
Include every required field
Your name and any trading name, your address, a unique sequential invoice number, the invoice date and due date, the client's name and address, an itemised list of what you did, the total, and your payment details.
Miss a field and you hand the client a reason to sit on the payment while they come back to ask you for it.
Stay VAT-correct
Add VAT only if you are VAT-registered, and show your VAT number alongside the rate and the amount. If you are not registered, do not charge VAT and do not show a VAT number at all.
Make payment easy
The fewer steps between your client reading the invoice and sending the money, the sooner you get paid. Bank transfer details or a payment link on the invoice itself beats a vague “let me know when you've paid”.
Save as PDF and send it
A PDF locks the layout so nothing gets edited in transit, and it opens the same way on every device. Email it with a one-line note that references the invoice number, so it is easy to find again later.
Follow up on time
Gently on the due date, then at 7, 14 and 30 days overdue. Keep the tone polite and factual, and attach the invoice every time so there is never an excuse about not having it. Our payment reminder templates cover the wording for all four stages.
Ready to send your first invoice?
Generate a compliant UK invoice in under a minute — free, no sign-up, no watermark.
The fields, at a glance
If you only remember one thing from this guide, remember the list. Every UK invoice needs these:
- Your legal name, plus any trading name you use.
- Your business address and contact details.
- A unique invoice number that never repeats and runs in sequence.
- The invoice date and an explicit due date.
- The client's name and address.
- An itemised description of each piece of work and its cost.
- The total owed and how to pay it.
- VAT details — only if you are VAT-registered.
Frequently asked questions
Do I need a company to invoice as a freelancer?
No. Freelancers and sole traders can invoice under their own name without forming a company.
Should I collect a deposit?
For new clients, or any project over a few hundred pounds, a 25–50% deposit protects your cash flow and filters out non-serious clients before you have done the work.
What do I do if a client doesn't pay?
Remind politely on the due date, then at 7, 14 and 30 days overdue. Keep it factual and attach the invoice each time. If it is still unpaid after a final notice, decide then whether to pause work or charge late fees as set out in your agreement.
How long should I keep copies of my invoices?
At least five tax years, or six if you are VAT-registered. Keep them with your expense records for self-assessment.
Free invoice tools
General guidance only — this is not legal, tax or accounting advice. Last reviewed 22 September 2026.