How to write an invoice as a freelancer in the UK (what to include)

An invoice is a request for payment, but it is also a legal and tax record. A clear one gets paid faster and keeps you on the right side of HMRC. This guide explains what a UK freelancer should put on an invoice, with practical tips on terms, VAT and late payment. It is general information, not legal advice.

What to include on every invoice

• The word “Invoice” clearly at the top.
• A unique invoice number. Number them in sequence, with no gaps or repeats.
• The invoice date, and the date of supply if it is different.
• Your name or business name and your address, plus your contact details.
• Your client’s name and address.
• A description of what you supplied, with quantities and rates.
• The amount due, with any discounts and a total.
• The payment terms and the due date.
• Your bank details and how to pay.

If you are VAT registered

A VAT invoice needs more: your VAT registration number, the VAT rate for each item, the amount of VAT charged and the total including VAT. Keep a copy of every VAT invoice for the period HMRC requires. If you are not VAT registered, never show VAT on your invoice.

Set clear payment terms

Say when payment is due, for example 14 or 30 days from the invoice date, and put a real date on the invoice. State how you want to be paid, and what happens if payment is late. Agreeing the terms in a contract or quote before you start work makes them much easier to enforce. For ideas that shorten the wait, see nine ways to get paid faster.

Describe the work properly

Vague lines such as “services” invite questions and delays. Name the project or deliverable, the period, and any purchase order number your client uses. Larger clients often reject invoices that do not carry their PO number.

When to send it

Invoice as soon as the work is done or as soon as a milestone is reached, not at the end of the month. Send it to the person who approves payments, and follow up politely the day it falls due.

If a client pays late

Under the Late Payment of Commercial Debts legislation, a business can charge interest on late B2B payments at 8% above the Bank of England base rate, plus fixed compensation of £40 for debts under £1,000, £70 for debts from £1,000 to £9,999.99 and £100 for £10,000 or more. These rights apply to business-to-business debts, so they do not cover consumers. Start with a friendly reminder, then a firm email, and consider a formal letter before taking further steps.

Correcting a mistake

If you issued an invoice with an error, do not delete it. Issue a credit note that cancels it and raise a new correct invoice, so your numbering and records stay clean.

How AvrioBooks helps

In AvrioBooks you pick a client, add products or services, and the invoice is numbered and totalled for you. Download it as a PDF or email it straight to the client. Issue credit notes when you need to correct one, and watch the aged receivables report to see which invoices are overdue. See Delete or correct an invoice for the steps, or read about AvrioBooks for freelancers.

Frequently asked questions

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