How to chase an unpaid invoice

Most of the work happens before the invoice#

The best chase is the one you never have to send, and most of what decides that is settled before you pick up a tool.

• ✓A deposit on anything with a real material spend, so you are never funding the job yourself
• ✓Payment terms written on the quote and repeated on the invoice, not assumed
• ✓A due date that is an actual date, not the phrase 'on completion', which nobody diarises
• ✓Bank details and a payment link on the invoice itself, so paying is easier than filing it
• ✓The invoice sent the day the job finishes, while the work is fresh and they are still pleased

If you are VAT registered, put the VAT and your VAT number on the document too. A query about the paperwork is one of the easiest reasons for a customer to park an invoice, and it is the one entirely within your control.

Chase on a schedule, not on a mood#

Chasing feels awful because it usually happens at the point of irritation, which is the worst moment to write anything. Decide the timings once and it stops being personal.

1. Day after the due date

   A short, friendly nudge that assumes it was overlooked. Most invoices are paid at this step.

2. Day 7

   Repeat the amount, the due date and how to pay. Same thread, so the history sits in one place.

3. Day 14

   Firmer. Say what interest you will add and what happens next, and give a date to pay by.

4. Day 30

   The formal letter of claim, by post, with the full pack of enclosures if the Protocol applies.

Two rules make the sequence hold. Send everything from the same thread or the same number, so the history is visible in one place. And stop the sequence the moment they reply with a plan, because a customer who has committed to a date and is still being pinged automatically is the one who tells everyone about you.

Three messages you can copy#

Change the names and the numbers. The structure matters more than the wording: state the amount, state the date, make paying the easiest thing available, and give them a way to reply that is not an admission.

Send the third one by post even if everything else has been email. That is what the Protocol expects, and a letter arriving on the mat lands differently to a notification.

What you are actually owed#

What you can add to the debt depends entirely on who the customer is, and the three cases are not close to each other.

A sole trader customer counts as a business, so chasing another trade gets you the statutory interest of the middle column. It also, separately, brings the Pre-Action Protocol into play, because that one turns on the customer being an individual. Those two rules point in different directions and both apply at once.

Subcontract work is a different game#

If you invoice a main contractor, a developer or a commercial client rather than a householder, you are almost certainly under the Housing Grants, Construction and Regeneration Act 1996, and it gives you weapons the domestic version of this problem does not have.

• ✓Payment notices and pay less notices: if they fail to serve a valid pay less notice in time, the notified sum falls due in full
• ✓Adjudication at any time, decided in about 28 days and binding until a court says otherwise, which is far faster than issuing a claim
• ✓The right to suspend performance on 7 days' written notice if a sum properly due is unpaid, and to recover the cost of stopping and remobilising

The catch is section 106: a contract with a residential occupier, meaning someone having work done on the home they live in or intend to live in, is carved out. So the same trade can have adjudication rights on Monday's subcontract job and none at all on Tuesday's kitchen. Worth knowing which one you are standing in before you threaten anything.

If they still will not pay#

The formal step before court is the letter of claim. Where the Pre-Action Protocol for Debt Claims applies, it sets out exactly what that letter must contain and how long you then have to wait.

• ✓Enclose an up-to-date statement of the debt, the information sheet, the reply form, and a financial statement form
• ✓Date the letter clearly at the top and post it that day or the next
• ✓The 30 days runs from the date at the top of the letter, not from when they receive it
• ✓If they return the reply form asking for time or documents, wait 30 days from the reply or from you providing the documents, whichever is later
• ✓If they reply and you cannot agree, give at least 14 days' notice before you issue
• ✓If you agree a payment plan and they later default, you start the Protocol again with a fresh letter of claim

None of this is optional decoration. The court will look at whether you complied in substance, and skipping steps can cost you your costs even on a claim you win. It is worth doing properly rather than quickly.

After that, the small claims track of the county court handles debts up to £10,000 in England and Wales, can be started online and does not need a solicitor. The issue fee is added to what the customer owes. Plenty of debts settle before a hearing and a good number settle at the letter of claim, because that is the point where it stops looking like a nag and starts looking like a process.

An old debt is not automatically a dead one. Under the Limitation Act 1980 you have six years from the date the debt fell due to bring a claim in England and Wales, and five under the Scottish rules. That is not a reason to leave it, because evidence and goodwill both decay long before the deadline does, but it does mean last spring's unpaid balance is still worth a letter.

Two things to weigh before you file: a judgment is not the same as money, and enforcement is a separate step with its own fee. On a small balance against a customer who plainly cannot pay, the honest answer is sometimes to write it off, learn the deposit lesson, and spend the evening on a job that pays.

What not to do#

• ✕Do not withhold keys, tools or the customer's property as leverage. That is not a lien and it can turn a simple debt into a claim against you
• ✕Do not rip out work you have already fitted. Once it is installed it is part of the building, retention of title will not save you, and you are risking criminal liability rather than a civil argument
• ✕Do not post about it. A named customer on social media is a defamation risk and it makes you look difficult to work with
• ✕Do not let it go quiet for months and then arrive angry. The gap undermines the debt
• ✕Do not threaten a step you are not going to take. The second empty threat is worth nothing

Write off the debt, keep the lesson#

If a debt is genuinely never coming in, the tax position depends on how you account. Since April 2024 the cash basis is the default for sole traders, and under it you never recorded the income, so there is nothing to write off and no bad debt claim to make. You still keep the relief on the materials and costs you actually paid for. If you opted out and use traditional accruals accounting, you declared the income when you invoiced and you can claim bad debt relief once the debt is genuinely bad. Keep the chase correspondence either way. It is the evidence.