How to chase an unpaid invoice in the UK

Confirm the amount, due date, agreed payment terms, payment details and any purchase-order requirements. Small administrative errors can delay payment even when the customer intends to pay.

Check that the invoice was sent to the right person and that the customer has everything needed to process it.

The Office of the Small Business Commissioner recommends a polite reminder as an early step. Include enough information for the customer to act: the invoice reference, amount, due date and payment instructions.

If the first reminder is ignored, follow up directly with the person responsible for payment rather than repeatedly sending the same message.

Keep the original invoice, contract or agreed terms, proof of completed work or delivery, emails and reminders. If the invoice later needs formal recovery, a clear record of what happened and when becomes much more useful.

For an eligible late commercial debt, statutory interest and fixed recovery compensation may be available. Check the official rules and any contractual late-payment terms before adding charges to a demand.

Read how UK late-payment interest is calculated, or see the £40, £70 and £100 recovery-compensation bands.

If friendly reminders do not resolve the invoice, a clearer documented follow-up can set out the outstanding amount, what you are asking the customer to do and a reasonable deadline for response or payment.

Avoid escalating the wording automatically if the customer has raised a genuine dispute that needs to be resolved first.

If the debt remains unresolved, later steps can include a final demand and seeking support. The Office of the Small Business Commissioner says it may be able to assist eligible UK small businesses with unresolved payment disputes involving larger customers.

Legal action or a collection agency is a more serious step. Consider the cost, evidence, commercial relationship and whether professional advice would be useful before proceeding.

Office of the Small Business Commissioner — Help with unpaid invoices ↗

LatePay Kit can check the basic eligibility questions, estimate potential late-payment charges and recommend a stage based on how overdue the invoice is.