How to invoice as a freelancer in the UK

Sending an invoice sounds more official than it is. For a sole trader who isn't registered for VAT, an invoice is simply a clear document that says who did what, for whom, for how much, and by when it should be paid. There's no special software you have to use and no form to file — you just need the right details on it and a sensible way to send it.

This guide walks through the whole thing in order: what to put on the invoice, how to number it, how to set payment terms, how to send it so you actually get paid, and what to do on the rare occasion a client pays late. Where something is a legal requirement rather than good practice, we'll point you to the official gov.uk page rather than paraphrase it.

One quick note before we start: TrustSolo isn't a law firm or an accountancy, and nothing here is legal or financial advice. It's a plain-English guide to help you invoice sensibly from the first job — one part of getting set up as a freelancer.

Put the right details on the invoice

An invoice only works if it leaves nothing to interpret. HMRC sets out the details every invoice must include, and for a sole trader who isn't VAT-registered the list is short:

• a unique identification number (more on numbering below)
• your name, and any business name you trade under
• an address where legal documents can be delivered, if you're using a business name
• the name and address of the client you're invoicing
• a clear description of what you're charging for
• the date the work was done, and the date of the invoice
• the amount being charged, and the total owed

That's genuinely all that's required. Everything else — your logo, a friendly note, the bank details you'd like to be paid into — is optional, and worth adding because it makes the invoice easier to act on. Bank details in particular: an invoice with no obvious way to pay it is an invoice that waits.

Here's how those details come together in practice.

INVOICE                                    Invoice no: INV-014
                                           Invoice date: 3 July 2026
From: Jordan Hale (Hale Copywriting)       Work completed: June 2026
2 Meadow Lane, Bristol BS1 2AB
jordan@halecopy.co.uk

To: Northgate Studios Ltd
14 King Street, Bristol BS1 4EF

Description                                              Amount
Website copy — 6 pages, agreed scope                  £1,200.00
                                              ─────────────────
                                          Total due    £1,200.00

Payment terms: 14 days — due by 17 July 2026
Pay to: Hale Copywriting · 12-34-56 · 1234 5678

A quick word on VAT

Most people starting out can ignore VAT entirely. You only have to register once your taxable turnover passes the VAT registration threshold — currently £90,000 over any rolling 12-month period. Below that, you don't add VAT and your invoice stays as simple as the one above. If you do register later, you'll need to issue fuller VAT invoices with a few extra details, including your VAT number — but that's a bridge to cross only if and when you reach it.

Give every invoice a unique number

The one detail people overlook is the invoice number. Each invoice needs its own unique identifier, and the tidy way to do it is a simple running sequence — INV-001, INV-002, and so on — so that no two invoices ever share a number and none goes missing.

It isn't bureaucracy for its own sake. Sequential numbering is how you (and, if it ever comes to it, HMRC) can see at a glance that your records are complete. It also makes a specific invoice easy to refer to when a client asks "which one was that again?" Pick a format on your first invoice and keep to it; the scheme matters far less than the consistency.

Set clear payment terms and a due date

Payment terms are simply how long the client has to pay. Fourteen or thirty days from the invoice date is typical for freelance work — shorter is better for your cash flow, longer is sometimes the price of working with bigger clients who have their own payment cycles.

Whatever you choose, do two things. Agree it before you start the work, so it's no surprise when the invoice lands. And put the actual calendar due date on the invoice — "due by 17 July" — not just "payable within 14 days." A concrete date is harder to lose track of, for both of you.

For a new client, or a larger piece of work, it's also perfectly normal to ask for a deposit up front — a portion of the fee before you begin, with the balance on completion. It secures a portion of your fee before you commit the time, and tends to filter out the clients who were never quite serious.

Send it promptly and make it easy to pay

Send the invoice as soon as the work is done, or at the agreed point in the job. This matters more than it seems: where no payment date has been agreed, the law treats a business payment as due 30 days after the client receives the invoice or you deliver the work — so the clock only starts when the invoice actually arrives. An invoice sitting in your drafts folder is money you've chosen to wait for.

Make it as easy as possible to pay. Bank transfer is the freelance default and costs nothing; a card or online payment link removes even the small friction of typing in your account details, which nudges the payment up the client's list. Keep a copy of every invoice you send, both for your own records and because HMRC requires you to keep business records for at least five years after the relevant Self Assessment deadline.

This is the part TrustSolo is built to take off your hands: it assembles the invoice with the details listed above, numbers it in sequence for you, sets the due date from your payment terms, and attaches a payment link so the client can settle it in a couple of clicks. You can see how it works under invoicing.

Chase late payment calmly — and know your rights

Most late payment isn't bad faith. The client is busy and the invoice has slipped down the pile, and a short, factual reminder — "just a note that invoice INV-014 was due yesterday; the details are below" — settles the great majority of cases without any friction at all.

If it genuinely drags on and your client is a business, the law is firmly on your side. Under the late commercial payments rules you have a statutory right to charge interest at 8% plus the Bank of England base rate on the overdue amount, and on top of that a fixed sum towards your debt recovery costs:

• £40 for a debt under £1,000
• £70 for a debt of £1,000 up to £9,999.99
• £100 for a debt of £10,000 or more

You'll rarely need to invoke any of this — often just mentioning that the right exists is enough to move a stubborn payment along. Our guide to late-paying clients sets out the full escalation ladder, from a first reminder to a court claim. (These rights apply to business clients. If you invoice private individuals, the position is different, and the practical route is a clear reminder followed, if it comes to it, by the small claims process.)

The better answer, though, is to prevent late payment rather than pursue it: a clear invoice, sent promptly, with a due date on it and an easy way to pay, is paid on time far more often than not.

Get those right and invoicing stops being a chore you dread and becomes a two-minute habit at the end of a job. When you'd rather not assemble it by hand each time, you can start free — no card required — and let the invoice, the due date and the payment link take care of themselves.