How to chase an unpaid invoice without falling out with the customer

Before it’s late

The easiest invoice to chase is one the customer knew was coming. Agree when you’ll be paid when they accept the quote, mention it again before you finish, and hand over the invoice the day you do.

Every invoice should show the date it’s due, your bank details and the reference to pay with. With a business customer, if you haven’t agreed a payment date, the law treats the payment as late 30 days after they get the invoice, or after you did the work if that’s later. GOV.UK: when a payment becomes late.

Day 3: a friendly nudge

Assume it’s been missed. Keep it short, and make paying one step.

Day 7: clear, still friendly

Say it’s still outstanding, ask when it’ll be paid, and leave the door open in case something’s wrong.

Day 14: firm and polite

Give a date to pay by, and ask them to ring you if they can’t.

When to ring instead

After the day 14 message, or sooner for a big amount or a customer you want to keep, pick up the phone. Ask if there’s a problem before you ask for the money. If they need time, agree a date or a few instalments, then confirm it by text so you both have it in writing.

• One message at each step, never a string of them.
• Keep it in writing: the messages are your record if it goes further.
• Never threaten anything you won’t do.

Business customers: interest and a fixed sum

The Late Payment of Commercial Debts (Interest) Act covers business customers only: a contractor you work for, a shop, an office. When another business pays you late, you can claim:

Statutory interest

8% plus the Bank of England base rate, unless your contract sets a different rate. GOV.UK works it out as a year’s interest divided by 365, for each day it’s late. To add it, send a new invoice.

A fixed sum for the cost of recovering it

£40 on a debt up to £999.99, £70 on £1,000 to £9,999.99, and £100 on £10,000 or more, once for each payment, on top of the interest.

Householders aren’t covered by it, which is one more reason to agree your payment terms on the quote.

From GOV.UK on interest and on debt recovery costs, and the Act itself, section 2 (contracts where both sides are acting in the course of a business) and section 5A. The Bank of England’s current Bank Rate. Checked 28 September 2026.

If it still isn’t paid

If you’ve chased, rung and written and it’s still unpaid, GOV.UK explains how to make a court claim for money, what used to be called the small claims court. It says there’s a different process in Scotland and in Northern Ireland.