How to Chase an Unpaid Invoice in the UK (Without Losing the Customer)

Most late payments are not a customer deciding to rip you off. They are an invoice that landed at the wrong moment, got buried, and then became awkward for the customer to bring up. Your job is to make it un-awkward, and to do it early.

Act on day one, not day thirty

An invoice that is one day late is not late. An invoice that is thirty days late has been forgotten and now needs a conversation you both find uncomfortable.

Send a short, friendly nudge the day after it was due. Short is the whole trick.

The escalation ladder

Day 1 overdue — friendly reminder. Assume it is an oversight, because it usually is. Name the invoice, the amount, and the date.

Day 7 — ask directly. Still warm, but now it needs an answer. Ask them to confirm when it will be paid rather than asking if they have seen it. A question with a date in it gets a reply.

Day 14 — phone them. Email is easy to ignore. A thirty-second call resolves most of these, and it is far less confrontational than it feels.

Day 30 — put it in writing. A formal letter or email stating the amount, the days overdue, and the fact that statutory interest is now accruing.

Beyond that — decide. Chase formally, use a recovery service, or write it off and stop working for them. What you should not do is keep supplying.

What you can legally add

For business-to-business debts, you are entitled to charge statutory interest at 8% above the Bank of England base rate, plus a fixed sum towards your recovery costs. That is the legal default where nothing else was agreed — it is not a favour you are asking for.

Our late payment interest calculator works out the exact figure, but the important part is not the money. Naming it changes the tone: you stop being someone asking a favour and become someone applying agreed terms.

The rate that applies is the one in force on the day the debt arose, not today. And it applies to commercial debts, not to work you did for a consumer.

The same three sentences still happen to be the best template

I'm following up on invoice 1042 for £840, which was due on 14 September.

Could you confirm the date it will be paid? If it has been approved and is waiting on a payment run, let me know which date that is and I'll update my records.

For transparency, our terms now include statutory interest on overdue commercial invoices. I'd much rather sort this without adding anything to the bill.

That last line is the one that works. It is courteous, it is true, and it quietly explains what happens next.

Stop the next one

The reason people spend their evenings chasing invoices is that chasing is a manual job. A reminder that goes out automatically, on the day, every time, does not get forgotten — and it removes the awkwardness because a system sent it rather than you.

That is the part FlowSync automates: deposit due, sent, overdue, chased. See the invoice automation or try it free for 14 days.

If cash flow is the immediate problem rather than the process, the job profit calculator is worth ten minutes — overdue invoices are one of the fastest ways a profitable job becomes a loss.