Discover how to write particulars of claim for an unpaid invoice small claims case in England and Wales, with a worked example from ClaimsPilot.
Example particulars of claim for unpaid invoice — prepared with ClaimsPilot
Chasing an unpaid invoice through the courts can feel daunting, particularly when you reach the stage of filing your claim and are faced with a blank text box asking you to explain your case. The “particulars of claim” section of the claim form is where you set out the facts, the amount owed, and the legal basis for your claim — and getting it right matters. A vague or incomplete statement can weaken your position, delay proceedings, or even result in your claim being struck out.
This article walks through what particulars of claim need to include for an unpaid invoice dispute, provides a worked example, and explains how ClaimsPilot can help you draft a clear, court-ready statement before you file.
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What are particulars of claim?
When you issue a claim through HMCTS Money Claim Online (MCOL) or by filing a paper N1 claim form, you are required to provide particulars of claim. This is a concise written statement — typically no more than a few paragraphs — that tells the court and the defendant:
- Who you are and who the defendant is
- The nature of the contract or agreement between you
- What the defendant did (or failed to do) that gives rise to your claim
- The amount you are claiming and how it is calculated
- Any interest you are seeking
The Civil Procedure Rules (CPR) govern the content and format of particulars of claim. For small claims — those valued at up to £10,000 in England and Wales — the rules are relatively straightforward, but clarity and completeness are still essential.
It is worth noting that particulars of claim are a statement of the facts of your case, not a place to express frustration or make accusations. Courts expect neutral, factual language.
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What to include in particulars of claim for an unpaid invoice
For an unpaid invoice claim, your particulars should cover the following key elements.
The contract
Explain how and when the contract was formed. Was it a written contract, an exchange of emails, a verbal agreement confirmed in writing, or a purchase order? State the date the agreement was made and what services or goods were to be provided.
Performance
Confirm that you fulfilled your side of the agreement. For services, state when the work was completed. For goods, state when they were delivered. This is important — you cannot claim payment if you have not demonstrated that you delivered what was agreed.
The invoice
State the invoice number, the date it was issued, the payment terms (for example, payment due within 30 days), and the date on which payment became due.
Non-payment
Confirm that the defendant has failed to pay, despite the invoice being due. If you have sent reminders or a formal letter before action, you can note this briefly.
The sum claimed and interest
State the principal amount owed. If you are also claiming statutory interest under the Late Payment of Commercial Debts (Interest) Act 1998 (for business-to-business debts) or interest under the County Courts Act 1984, set out the rate, the period, and the daily rate accruing. You can use the ClaimsPilot interest calculator to work out your figures accurately before you draft your statement.
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A worked example: particulars of claim for an unpaid invoice
The following is an illustrative example based on a fictional scenario — a sole trader providing web design services to a limited company. This is for guidance only and does not constitute legal advice.
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IN THE COUNTY COURT
Claimant: Sarah Ahmed (trading as SA Web Design)
Defendant: Brightfield Retail Ltd
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Particulars of claim
1. The Claimant is a sole trader providing web design and development services. The Defendant is a company registered in England and Wales.
2. By an agreement made on or around 14 January 2025, evidenced by a written contract dated 14 January 2025 and signed by both parties, the Claimant agreed to design and develop a website for the Defendant in exchange for payment of £3,200 plus VAT.
3. The Claimant completed the agreed work and delivered the finished website to the Defendant on 28 February 2025, as confirmed by email correspondence dated 28 February 2025.
4. On 3 March 2025, the Claimant issued Invoice No. SA-2025-047 to the Defendant in the amount of £3,840 (including VAT at 20%), with payment due within 30 days, namely by 2 April 2025.
5. The Defendant has failed to make any payment in respect of the said invoice, despite the Claimant sending payment reminders on 8 April 2025 and 22 April 2025, and a formal letter before action on 5 May 2025.
6. The Claimant claims the sum of £3,840, being the outstanding invoice amount.
7. The Claimant further claims statutory interest pursuant to section 69 of the County Courts Act 1984 at the rate of 8% per annum from 2 April 2025 to the date of judgment or earlier payment. Interest accruing at £0.84 per day. As at the date of filing (20 May 2025), interest amounts to £15.12.
AND the Claimant claims:
(a) £3,840.00 (principal sum)
(b) £15.12 (interest to date of filing)
(c) Further interest at £0.84 per day until judgment or payment
(d) Court fees
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This example demonstrates the level of detail courts expect: specific dates, invoice numbers, amounts, and a clear narrative of what happened. Notice that the language is factual and unemotional — there is no commentary on how unprofessional the defendant has been or how stressful the situation has felt.
If the debt is between two businesses (rather than a business and a consumer), you may be entitled to claim interest at the higher rate of 8% above base rate under the Late Payment of Commercial Debts (Interest) Act 1998, as well as fixed debt recovery costs. ClaimsPilot’s interest calculator can help you determine which basis applies and calculate the correct figures.
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Steps to take before you file your claim
Courts in England and Wales expect claimants to follow pre-action protocols before issuing proceedings. For debt claims, this means sending a formal letter before action that gives the defendant a reasonable opportunity to respond — typically at least 30 days for business debts. The relevant guidance is set out in the Pre-Action Protocol for Debt Claims.
If you have not yet sent a letter before action, you should do so before filing. ClaimsPilot’s letter before action tool generates a properly formatted, protocol-compliant letter tailored to your circumstances — including the correct payment deadline and details of what happens if the defendant does not respond.
Sending a strong letter before action can also prompt payment before you need to go to court at all. Many disputes are resolved at this stage once the defendant realises you are serious about pursuing the matter.
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How ClaimsPilot helps you prepare your particulars of claim
ClaimsPilot is designed specifically for individuals and small businesses bringing straightforward money claims in England and Wales. Rather than starting from scratch, ClaimsPilot guides you through the key details of your dispute and generates a structured draft that you can review, adapt, and use when filing your claim.
For unpaid invoice claims, ClaimsPilot helps you to:
- Structure your narrative — by prompting you for the right information in the right order, so nothing important is left out
- Calculate your interest — using the built-in interest calculator to produce accurate figures for your