AnswersWhen a client won't pay
My client says they never received my invoice. What do I do?
The short answer
Resend it today. Send the same invoice again, with the same number and date, to their accounts mailbox and to your contact, and ask for a reply with the payment date. If you agreed a fixed payment date, that date stands4 even if the invoice did not arrive. If you agreed none, the 30 days start when they get the invoice1, so each day you wait pushes the date back a day.
England and Wales only. WolfX is software, not a law firm.
What you can add
A £2,950 invoice that went missing
Say you emailed a £2,950 invoice on Tuesday 1 September 2026, on terms of 30 days from invoice date, so it fell due on Thursday 1 October. On Monday 5 October the client says it did not arrive. You resend it that day with a pay-by date of Monday 19 October, and they pay on 19 October: 18 days late. The rate is 8%6 above Bank Rate7 of 3.75%, so 11.75% a year, for any invoice that went late between 1 July and 31 December 2026.
The date was agreed, so the resend did not move it. With no date agreed, the 30 days would run from 5 October, interest would start on 4 November, and it would grow by 95p a day.
The road ahead
Six steps. A stamp at most.
Step 1: Check what you sent
Open the sent email and note the date, the time, the address and any bounce message. Check the address against the one their accounts team uses: the person who ordered the work may not be the one who pays11.
Step 2: Gather what shows it went
A sent item with the full header and no bounce shows you sent it, not that it arrived. A portal receipt, or an earlier email that mentions the invoice or the price, shows more. A read receipt shows little.
Step 3: Read the payment line in your terms
If you agreed a date, it stands4. One counted from the invoice date ("30 days from invoice date") does not wait for the invoice to arrive; one counted from receipt ("30 days from receipt") moves with it. If you agreed none, see when an invoice is officially late.
Step 4: Resend the same invoice today
Send it to the accounts mailbox and to your named contact, marked as a copy, with the same number and date. Use the email below, and don't wait for them to confirm first.
Don't re-issue it under a new number or date. That makes a duplicate and can move the date.
Step 5: Post a copy if the sum is large
The law lets you send a document to a company by post to its registered office8, which you can find on Companies House9. Keep the proof of postage; proving it arrived has its own page.
The court's dates for when a posted document counts as served, rule 6.2610, cover documents in a claim, not invoices.
Step 6: Count from the due date, not the resend
Interest and the fixed sum follow the due date. If the pay-by date passes with no reply or payment, send a firm reminder with the sum worked out, and from day 30 late a letter before action.
A letter you can copy
Resend email asking them to confirm
Send it the day they say the invoice did not arrive, with the invoice attached again.
Tap a highlighted gap to see what goes in it.
Send it in one email to both addresses, so the sent copy shows both, and keep it with the invoice. Ask for a reply, not a read receipt. A reply is a record of when they had it.
When not to bother
When it isn't worth it
- They have already replied to, paid part of, or discussed this invoice. Then they plainly have it. Skip the resend and go straight to chasing the payment.
- "Not received" is really a dispute about the work or the price. Resend anyway; if the reply argues about the job, move to what happens when a client disputes an invoice.
- It is a first invoice to a new client and one resend settles it. Send the copy, keep the sent email, and leave the rest.
- The client is a consumer. The late payment law only covers sales between businesses5, and consumer rules differ.
The Wolf's note
Whether it arrived matters less than the payment line in your terms. Resend today, to two places, and keep the sent copy. A reply with a date in it settles more than any read receipt.
Mr. Wolf · the AI inside WolfX
What comes next
Your next move
When is an invoice officially late?
An invoice is late the day after the agreed date.
5 min read · Letter included
If they push back
What proof do I need to show I did the work and they owe me?
Proof is five kinds of paper: the deal, the work, their acceptance, your invoice and your chasing.
7 min read · Letter included
So it doesn't happen again
What must be on an invoice for it to be valid and get paid?
Nine things go on any invoice, plus the VAT items if you charge VAT.
6 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.