What late payment wording should go on my invoice?
The short answer
Two lines. One says late payment carries interest at 8% a year over the Bank of England base rate3; the other adds a fixed £40, £70 or £100 by invoice size4. Add the due date and your bank details. The law writes interest7 and the fixed sum10 into a sale to another business, so the lines only tell the customer what is coming.
England and Wales only. WolfX is software, not a law firm.
What you can add
A £1,800 invoice, 30 days late
Say you invoiced another business £1,800 on 1 October 2026, due on 31 October, the date you agreed, with the two lines at the foot. By 30 November it is still unpaid: 30 days late. It went late in the second half of 2026, so the rate is the 3.75% base rate plus 8%, which is 11.75%6.
Every day after that adds another 58p, until they pay. The sum is the same if the invoice says nothing; the two lines mean the customer has seen it coming.
The road ahead
Five steps. Fifteen minutes. All free.
Step 1: Agree the date before the job
Put the pay-by date in your quote or contract, so the invoice only repeats what the customer said yes to. A date counts as the due date only if they agreed it9; the interest and the fixed sum need no agreement.
Step 2: Write the due date as a date
Step 4: Add what they need to pay you
Add the invoice number, your bank details and the name of the person who approves payments. Then email it to that person and keep the sent copy.
Step 5: Leave off what you can't back
No fee you made up: the law sets the fixed sum, plus the difference if your reasonable recovery costs are higher10. A late fee of your own has to be agreed with the customer11; one first seen on the invoice has not been.
No threats of court action until you are ready to take it. Plain words read like a price list; legal-sounding ones read like a quarrel.
A letter you can copy
The foot of your invoice, ready to paste
Paste it under the totals on every invoice to a business, changing only the gaps.
Tap a highlighted gap to see what goes in it.
The subject line is for the email that carries the invoice. The rest goes at the foot of the invoice itself. Send it to the named person and keep the sent copy: it dates your record.
When not to bother
When it isn't worth it
- You sold to a consumer. The Act covers sales between businesses8. A sale to a homeowner needs different wording, and this page doesn't cover it.
- Your contract has a late fee of its own. A substantial one replaces the Act's interest12, so copy its wording on the invoice.
- Your customer is a council or other public authority. Interest on its debts starts after 30 days9 even if you agreed a later date, so print a due date inside that.
- The invoice has already gone late. Wording on an old invoice changes nothing. Add the interest with a letter instead.
The Wolf's note
The right was yours before the footer existed. The footer makes the price of paying late visible while there is still time to avoid it. Put it in your invoice template once, with a real date on every invoice, and any chasing later starts from words they have already read.
Mr. Wolf · the AI inside WolfX
What comes next
Your next move
Can I charge interest on a late invoice?
Yes, if you sold to another business.
3 min read · Letter included
Can I charge my own late fee on an invoice?
Yes, if your customer agreed the fee before the work and it is a substantial remedy.
6 min read · Letter included
When it first goes quiet
When is an invoice officially late?
An invoice is late the day after the agreed date.
5 min read · Letter included
Don't want to do this yourself?
The Wolf does every step for you. He works out the sums, writes the letters and keeps track of every date. Nothing goes without your yes.