How to Write a Dispute Letter to a Customer Who Won't Pay

A customer owes you money. You have sent reminders, made phone calls, and given them every reasonable chance to pay. Now you need to send a formal dispute letter — the legal step before taking court action.

A well-written dispute letter achieves two things: it shows the customer you are serious, and it gives you evidence that you followed proper process if the case ends up in court. Here is how to write one that works.

What is a letter before action?

A letter before action (also called a letter before claim) is a formal notice giving the debtor a final deadline to pay. Courts in England and Wales expect you to send one before making a claim — going straight to court without one may count against you.

The letter should be clear, factual, and give a reasonable deadline — usually 14 days.

What to include in your dispute letter

An effective dispute letter includes:

• Your details — your name, business name, address, and contact details
• The debtor's details — their name and address
• The date — when you are sending the letter
• A clear subject line — "Final Notice: Outstanding Payment for [Job Description]"
• The amount owed — the exact figure, broken down if necessary
• The original terms — reference to the agreed price, the date work was completed, and when payment was due
• A timeline — dates of previous reminders and attempts to contact the debtor
• A final deadline — 14 days is standard
• The next step — that you will take legal action if payment is not received

Example structure

Here is a template showing the structure. Replace the placeholders with your specific details:

Your Name
Your Business Name
Your Address
Your Phone
Your Email

[Date]

Customer Name
Customer Address

Subject: Final Notice — Outstanding Payment for [Job Description]

Dear [Customer Name],

I am writing to give you formal notice that you owe £[amount] for work carried out at [address] on [date(s)].

The work was agreed at a price of £[amount], as confirmed [in our signed contract / in writing on [date] / verbally on [date]]. The work was completed on [date], and payment was due on [date].

I have contacted you on [date], [date], and [date] to request payment. To date, I have received no payment and no explanation for the delay.

I am now giving you 14 days from the date of this letter to settle the outstanding amount in full. Payment should be made to [bank details / payment method].

If I do not receive payment by [deadline date], I will have no option but to take legal action to recover the debt. This may include a claim through the county court small claims track, and you may be liable for court fees and interest.

[Optional for B2B work: Under the Late Payment of Commercial Debts (Interest) Act 1998, I am entitled to charge interest at 8% plus the Bank of England base rate on overdue invoices, as well as fixed compensation costs.]

I hope this matter can be resolved without further action. If you have any questions or wish to discuss a payment plan, please contact me immediately.

Yours sincerely,
[Your Name]

Important legal references

For B2B transactions (e.g., you are a subcontractor working for a main contractor), the Late Payment of Commercial Debts (Interest) Act 1998 gives you a statutory right to charge interest at 8% plus the Bank of England base rate. You can also claim fixed compensation: £40 for debts under £1,000, £70 for debts between £1,000 and £10,000, and £100 for debts over £10,000. Reference this Act in your letter if applicable. For more detail, see our article on charging interest on late payments.

For consumer work (work directly for a homeowner), the underlying contract is covered by the Consumer Rights Act 2015. The right to charge interest comes from your contract terms, so reference your contract if it includes a late payment clause.

Tone and delivery

Keep your tone professional and factual. Aggressive or threatening language weakens your legal position. State the facts, reference the agreed terms, and make it clear you are prepared to take action. Send the letter by recorded delivery or email with read receipt. Keep a copy and proof of delivery.

If 14 days pass without payment, you can proceed to a small claims court application for amounts up to £10,000. For more on handling non-payment, including prevention strategies, see our guide on protecting yourself before the job starts.

A signed TradeContract makes dispute letters much more effective — you have got proof of everything agreed. Try it free.