Before the Relationship Sours: A Late-Payment Paper Trail for UK Micro-Businesses

Late payment is rarely a single dramatic event. It is usually a sequence of small delays: a missing purchase order, a finance contact on leave, a query raised late, a promise that slips by a week. For UK micro-businesses in 2026, where cash margins are often thin, those small delays can become a material finance issue. The most effective response is not a stern letter after sixty days. It is a documented, proportionate escalation ladder prepared before the first invoice leaves the business.

Agree the payment mechanics before work begins

The readiness work starts in the contract and the order confirmation, not in the credit control folder. Payment terms should be clear, written into the agreed contract and repeated on the invoice. They should identify the due date, the accepted payment methods, where invoices must be sent, whether a purchase order number is required and who is authorised to approve payment. If the business uses standard terms, those terms should include an interest clause and preserve the right to claim statutory interest and compensation where applicable.

The Late Payment of Commercial Debts (Interest) Act 1998 provides a fallback for many business-to-business debts, but it is not a substitute for clear terms. Where a contract already provides a substantial remedy for late payment, the statutory regime may not apply in the same way. A solicitor can confirm the position for a particular contract. For most micro-businesses, the practical goal is simpler: make the payment route unambiguous and keep a signed or confirmed copy of the terms with the order.

Start the evidence log on day one

A late-payment process is only as strong as its records. Keep a simple log for each invoice, recording the invoice number and date, the due date, the amount, the contract or purchase order reference, the date the goods or services were delivered, the named contact and any purchase order approval. Add every reminder sent, every reply received and a short note of any telephone call, including the date, time and what was agreed.

Store correspondence in a shared business folder rather than a personal inbox. Save the original invoice, the delivery evidence, the statement of account and any signed terms. The log should be contemporaneous and factual. It is not a tool for pressure. It is a record that allows the business to resolve a query quickly, show that reminders were sent and support a formal claim if the relationship deteriorates.

A three-step escalation ladder

Step one: the same-day courtesy reminder

On the due date, send a short courtesy note. It should assume oversight and make payment easy to complete. A useful template is:

Subject: Invoice [number] due today

Hello [name], I am writing to confirm that invoice [number] for [amount] is due today. If payment has already been scheduled, please disregard this note. If anything is outstanding, please let me know the expected payment date. Kind regards, [name and business]

Record the date and time of the reminder in the evidence log. This first step protects the relationship while establishing that the due date has been noted.

Step two: the formal reminder at seven days overdue

If the invoice remains unpaid, send a formal reminder. Reference the contract, attach the invoice and a statement of account, and ask for a specific payment date. If the contract permits it, state that further supply may be paused. Template wording could read:

Subject: Overdue invoice [number] — payment date required

Dear [name], invoice [number] for [amount] was due on [date] and remains unpaid. Please confirm by [date] when payment will be made. If there is a query about the invoice, please tell us now so that it can be resolved. We reserve all rights under the contract and applicable law. Further work may be suspended if payment is not received.

This step should be firm but not theatrical. The aim is to obtain a dated commitment or to surface a dispute early. If a payment plan is offered, record the agreed dates and amounts in writing and continue to monitor them.

Step three: the formal demand at fourteen to twenty-one days overdue

Where there is no payment and no credible plan, issue a formal demand. This is the point to cite the Late Payment of Commercial Debts (Interest) Act 1998 and to set a final deadline. A proportionate template is:

Subject: Formal demand — invoice [number]

Dear [name], despite previous reminders, invoice [number] for [amount], due on [date], remains unpaid. This is a formal demand for payment within seven days. If payment is not received, we will claim statutory interest and compensation under the Late Payment of Commercial Debts (Interest) Act 1998, together with reasonable recovery costs. We may also suspend further supply and take debt recovery action. If you believe there is a dispute about the invoice, please provide full details immediately.

What the Act allows

For qualifying commercial debts, the 1998 Act provides statutory interest at 8% above the Bank of England base rate, together with fixed compensation. The fixed sums are £40 for debts under £1,000, £70 for debts between £1,000 and £9,999.99, and £100 for debts of £10,000 or more. Reasonable additional recovery costs may also be claimed in some circumstances. Interest generally runs from the day after the agreed due date. These rights can be varied by a valid contractual term, so the contract should be checked before a claim is made.

Define stop-supply triggers in advance

A late-payment ladder needs a clear point at which the business pauses further supply. Decide the triggers before the first invoice is sent. Common triggers include an invoice being twenty-one days overdue with no agreed plan, a broken payment promise, a credit limit being exceeded, or a pattern of repeated late payment. Before suspending supply, check that the contract permits it, give notice in writing and avoid acting in a way that could amount to a repudiatory breach. Where an invoice is genuinely disputed, take advice before stopping essential supply.

Escalate beyond the ladder when needed

If the formal demand is ignored, the next steps may include a letter before action, debt recovery, mediation or a credit check on the debtor. The evidence log should make those steps easier and less expensive. Good records also help the business decide whether to continue the relationship at all. Late payment should not become interest-free credit by default. A prepared ladder gives the business a fair, documented route from a friendly nudge to a formal demand, while keeping the commercial relationship as intact as the circumstances allow.