How to Chase an Unpaid Invoice in the UK: Step-by-Step

An unpaid invoice is not just an inconvenience: it's your money, sitting in someone else's account. UK law is firmly on your side: you have a statutory right to chase what you're owed, add interest, and take a client to court if it comes to that.

This guide walks through the whole process in order, from your first polite reminder through to Money Claim Online, with the wording, timings, and rules a credit controller would actually use. Work through it in sequence and most invoices never need to go past step two.

You are not an outlier for having to chase. For the full, sourced picture of how big the problem is, see our UK late payment statistics reference.

This guide assumes a UK-based debtor. If your client is based outside the UK, several of the steps below work differently, our guide to chasing an unpaid invoice from an overseas client covers exactly what changes.

1. First, check the basics (before you chase)

Before you send anything, check four things. Getting this wrong wastes a chase cycle and gives a difficult client a reason to stall further.

• Is the invoice itself correct? Right amount, right reference, right business name and address.
• Were your payment terms clear? Stated on the invoice, in a contract, or agreed by email before the work started.
• Has the due date actually passed? Chasing a day early undermines you.
• Are you contacting the right person? Accounts payable, not just whoever commissioned the work; copy both in.

If any of this is missing or unclear, sort it before you chase. A vague invoice is the easiest thing for a client to hide behind.

2. The escalation timeline at a glance

Chasing an unpaid invoice works best as a fixed sequence, not an improvised argument. Escalate the tone and the consequences in stages, and give the client a clear, reasonable window to respond at each one before you move to the next.

This timeline is about pacing your escalation well, not the outer legal deadline for acting at all. For exactly how long you have before a court claim becomes time-barred, see our guide to how long you have to chase an unpaid invoice in the UK.

3. Step 1: The polite reminder (days 1–7)

Send this on the day the invoice becomes overdue, or the next working day. Assume it's an oversight: most late payments are. Keep it short, friendly, and specific: which invoice, how much, and the original due date. Email is fine at this stage; there's no need to call yet.

See more reminder wording for different situations in our payment reminder templates guide.

4. Step 2: The firm chase (days 7–14)

If seven days pass with no reply and no payment, the tone changes. Reference the original invoice and due date directly, state how many days overdue it now is, and ask for a specific payment date rather than a vague "soon". This is also the point to pick up the phone: a short call plus a follow-up email in writing works better than either alone. Keep a note of who you spoke to and what they said.

5. Step 3: Adding statutory interest and compensation

If a client still hasn't paid and there's genuinely no dispute about the invoice, you're entitled to more than just the original amount. The Late Payment of Commercial Debts (Interest) Act 1998 gives every business-to-business creditor in the UK a statutory right to charge interest on the overdue amount, plus a fixed sum of compensation for the cost of chasing it.

Statutory interest is calculated at the Bank of England base rate (3.75% following the Monetary Policy Committee's decision on 18 June 2026) plus 8%, a combined rate of 11.75% a year, applied daily from the day after the due date until you're paid. Checked 3 July 2026. The base rate can change at each MPC meeting, so confirm the current figure before quoting it to a client.

On top of interest, you can add a fixed compensation amount, set by the size of the debt:

You can claim this compensation as soon as the debt is late; you don't need to have spent that much chasing it, and if your actual recovery costs are higher, you can claim the shortfall too.

Add both figures to your next letter: it signals that you know your rights, and it's often the point a client decides paying is simpler than ignoring you further.

Read more in our guide to statutory interest on late payments, or use our free late payment interest calculator to work out the exact figure for your invoice. For the calculation walked through step by step, plus exactly how to word it to a client, see our guide to charging interest on overdue invoices. If "interest", "compensation", and "late payment fee" all sound like the same thing to you, they aren't. See our guide to what you can actually charge under each name for exactly how they differ.

6. Step 4: The final demand (days 14–30)

By day 14 to 30, you're past being patient. A final demand needs to read differently from everything before it: a firm deadline (7 to 14 days is standard), the exact total including interest and compensation, and a plain statement of what happens if it isn't paid: typically that you'll send a formal letter before action.

Don't threaten anything you're not prepared to follow through on; an empty threat costs you credibility at exactly the point you need it most.

7. Step 5: Letter before action (day 30+)

If the final demand deadline passes with nothing, the next letter is a letter before action (LBA), sometimes called a letter of claim. This is the last step before court, and for many clients it's the one that actually gets a response.

If your client is an individual or a sole trader, this letter is governed by a specific set of rules: the Pre-Action Protocol for Debt Claims. It sets out what the letter must contain: an up-to-date statement of the debt, how interest is calculated, a Financial Statement Form and Reply Form for the debtor to use, and at least 30 days before you can start court proceedings if they don't reply.

If your client is a limited company, this specific protocol doesn't technically apply, but the courts still expect you to have followed the general pre-action conduct rules, a clear letter, a fair deadline, and a genuine chance to pay or respond, before you issue a claim. Skipping this can cost you at the costs stage even if you win.

Courts expect to see that you sent an LBA before you ask them to get involved, and in our experience, most clients who were always going to pay eventually pay at this stage: a formal letter with a court threat behind it concentrates minds in a way three friendly emails don't. That's been true in credit control for as long as the process has existed, long before any of it went digital.

Read the full breakdown in our letter before action guide.

8. Step 6: Court: Money Claim Online and small claims

If the letter before action doesn't work, and you're confident the debt isn't genuinely disputed, the next step is Money Claim Online (MCOL), HM Courts & Tribunals Service's online system for claims up to £100,000. For most freelancer and small business invoices, this puts you on the small claims track, which is designed to be used without a solicitor.

The process, in outline: you register with MCOL, enter the claim details and amount (including your statutory interest and compensation), pay the court fee, and the court serves the claim on the debtor. They then have 14 days to respond, admit the debt, or dispute it. If they don't respond at all, you can apply for default judgment. Court fees are set by claim value:

Realistically, budget several weeks to a few months from filing to judgment if the claim is undefended, longer if the debtor disputes it and it goes to a hearing. Winning a judgment isn't the same as being paid: if the debtor still doesn't pay, you'll need a separate enforcement step (a warrant of control or third-party debt order, for example), which carries its own fee and timeline.

Court should be your last resort, not your first move. Most invoices that go through the earlier stages properly, a clear reminder, a firm chase, a costed final demand, a compliant letter before action, are paid before a claim form is ever filed.

If you're weighing whether filing is even worth it on this debt, our free small claims worth-it calculator weighs the court fee and your time against what you'd actually recover. Full walkthrough in our small claims court guide.

Not sure you want to run a claim yourself? Handing the debt to a debt collection agency for a cut of the recovery is the main alternative, and our guide on using a debt collection agency versus doing it yourself weighs that trade-off honestly.

9. How to avoid this next time

The best invoice to chase is the one you never have to send. A few habits make the biggest difference.

Take a deposit on anything above a token value. 20–50% upfront is standard for freelance and small-agency work, and it filters out clients who were never going to pay reliably: if someone balks at a deposit, that's information worth having before you start the work, not after.

Get your terms agreed in writing before you start, even if it's just a confirming email. 30 days is the statutory default if nothing is specified, but there's nothing stopping you agreeing 14 days, or 7 for a new client, and having it in writing removes any argument about what was promised.

Run a basic credit check on new clients above a certain invoice value, especially companies you haven't worked with before. A few minutes checking Companies House filings and payment history is cheaper than a bad debt.

Tracking due dates and reminders by hand gets harder as the number of invoices in flight grows. That's usually the point freelancers move off a spreadsheet and into proper accounting software, such as Sage^(affiliate), which flags overdue invoices automatically rather than relying on you to notice.

10. FAQ