How a UK supplier should document an overdue invoice for delivered goods

If a business customer hasn’t paid for goods you delivered, the most important thing is to create and preserve a clear paper trail that proves what you supplied, when it was delivered, the agreed payment terms, and every attempt you made to collect. That documentation is the basis for charging statutory interest, making a court claim, or — against a company debtor — serving a statutory demand; without it you weaken your position and may fail to meet the court’s expectations for pre‑action conduct.

The remainder of this guide explains exactly which documents matter, how to record interest and recovery costs correctly for B2B sales, what courts expect you to have done before starting proceedings (Money Claim Online guidance), and the realistic next steps if informal collection fails.

What evidence courts and collection channels actually want

Start by assuming a judge will look for the basics. Keep originals and date‑stamped copies of:

• The original sales invoice showing the amount, invoice date and payment terms (net days, payment method).
• Delivery note and proof of delivery or acceptance (signed delivery receipt, signed goods‑in note, or a carrier’s POD). This proves the goods were supplied and accepted.
• The underlying contract, order confirmation or written terms that set the agreed price and payment timetable — and any clause about interest or recovery costs.
• All reminders and correspondence (emails, letters, SMS, and contemporaneous phone‑call notes) showing you chased payment and the debtor’s responses. The Money Claim Online user guide emphasises keeping records of pre‑action contact because courts expect parties to try to settle before issuing a claim; preserve dated copies of those contacts and any attachments you sent (Money Claim Online user guide).

Why this matters: when you start a County Court claim you will rely on these documents as primary evidence. If you add statutory interest or recovery costs, you should send a fresh invoice or written notice showing how interest was calculated and when it began (Charging interest on late commercial payments).

When you can add statutory interest and recovery costs (B2B only)

For business‑to‑business debts the Late Payment of Commercial Debts (Interest) Act 1998 lets suppliers charge statutory interest and claim a fixed recovery sum where the debt qualifies. The statutory interest rate is the Bank of England base rate plus 8% for qualifying commercial debts; the primary legislation sets out the entitlement and calculation rules (Late Payment of Commercial Debts (Interest) Act 1998).

Practical points:

• Check your sale is a qualifying commercial debt — the rules do not apply to consumer sales.
• If you add interest, issue a revised invoice or a separate written calculation so the debtor and any court can see how the figure was reached (Charging interest on late commercial payments).
• The Act also allows a fixed recovery amount to be added for small debts after a certain point; the government guidance explains when and how to claim it.

If the buyer disputes liability or quality, adding interest may be contested. Keep records that show the goods were delivered and accepted to strengthen your right to interest.

The pre‑action stage: why recorded chasing matters and what to show

Courts expect reasonable pre‑action conduct. For England & Wales, the Money Claim Online guidance and MCOL user guide set out that before issuing a claim you should have taken practical steps to resolve the dispute and be able to show evidence of those steps (Money Claim Online user guide).

What to record:

• A clear, dated timeline of events (order, delivery, invoice sent, reminders, any agreed extensions).
• Copies of reminder letters or emails and proof they were sent (read receipts are useful but not essential; saving sent emails and using signed-for post where appropriate is better evidence).
• A short, factual summary of any defence the debtor raises (e.g., short delivery, damaged goods) and your response. If the dispute is about quality, retain inspection reports and photographs.

Why: if you later start proceedings the court will look at whether you tried to resolve matters and followed proportionate pre‑action steps. Missing or vague pre‑action records reduces your credibility and can affect costs orders.

Escalation: court claims, judgments and statutory demands

If reminders and negotiation fail, your principal options are:

• County Court claim (Money Claim Online): for most unpaid invoices you can start a claim online in England & Wales. The gov.uk pages explain how to make a court claim and what you will need to prove the debt — typically your invoice, delivery proof and contract terms (Make a court claim for money).

• Obtaining and enforcing a judgment: if the court grants a County Court Judgment (CCJ), there are several enforcement tools (writs, bailiffs, charging orders). The court guidance explains enforcement options and practical next steps (Make a court claim for money – make a claim).

• Statutory demand (company debt): if the debtor is a limited company you may serve a statutory demand for a qualifying undisputed debt; a failure to pay or set aside the demand within 21 days can permit presentation of a winding‑up petition. This is a serious insolvency step — the Insolvency Act and gov.uk provide the rules and the required formality for service (When you can make a statutory demand, How to serve a statutory demand, Insolvency Act 1986 section 268 (Insolvency Act 1986)).

Practical caution: statutory demands and winding‑up petitions can have severe consequences for the debtor and expose the creditor to risk if the debt is genuinely disputed. Take legal or insolvency advice before using them.

A realistic example and decision checklist

Example: You supplied £12,000 of goods with 30‑day terms. Goods were signed for on delivery. Invoice not paid after 45 days. You should: (1) keep the signed delivery note and original invoice; (2) send a dated reminder email and a recorded‑delivery letter; (3) calculate statutory interest (base rate + 8%) and send a revised invoice showing that calculation; (4) keep clear records of all contact; (5) if still unpaid, consider Money Claim Online with the invoice, delivery note and reminders attached.

Decision checklist before court: Do you have the invoice, proof of delivery/acceptance, contract or terms, and dated reminders? If yes, you can usually proceed to MCOL. If the debtor is a company and you have an undisputed debt, a statutory demand is an option — but get advice first.

Differences across the UK and final cautions

Most of the procedural guidance above relates to England & Wales (MCOL and County Court routes). Scotland and Northern Ireland use different court systems (Sheriff Courts in Scotland) and have different forms and procedures; consult local official guidance before taking formal steps. The gov.uk materials linked above are the primary references for England & Wales procedures (for example the Money Claim Online guide and official pages on charging interest and statutory demands).

Good documentation is the most powerful tool you have. It lets you add lawful interest, meet pre‑action expectations, and, if necessary, present a clean, credible claim in court or a statutory demand for a company debtor. If you want professionally prepared documents based on information you supply — such as a clear demand letter or a structured collection pack — consider using an external drafting service that specialises in commercial debt letters, for example .

Sources cited in the text include the Money Claim Online user guide (Money Claim Online user guide), the official late commercial payments guidance (Charging interest on late commercial payments), the Late Payment of Commercial Debts (Interest) Act 1998 (Late Payment of Commercial Debts (Interest) Act 1998), statutory demand guidance (When you can make a statutory demand, How to serve a statutory demand), and insolvency rules and legislation (Insolvency Act 1986, Insolvency Rules 2016 (Insolvency Rules PDF)).

If the sums are modest, the government’s EX350 guide on county court debt recovery is a practical primer on small‑business claims and enforcement options (EX350 - debt recovery guide).

Sensible next step: gather the documents listed above, prepare a clear timeline, and decide whether a well‑documented reminder (with a revised invoice showing interest) will likely prompt payment — or whether it is time to start a formal claim or seek insolvency advice for a company debtor.

For help preparing a professional dispute document, BeforeSuit can help you prepare your next steps.