AnswersWhen a client won't pay
My client wants me to invoice a different company from the one I worked for. Should I?
The short answer
Only in writing. Until the company you contracted with agrees to the change, invoice that company. Late payment interest1 is a term implied in the contract, and the fixed sum, £40 to £100 by invoice size4, is treated as part of that term, so both are tied to the contract you signed, not to whose name is on the invoice.
England and Wales only. WolfX is software, not a law firm.
What you can add
A £6,500 invoice, 17 days late
Say you invoiced a client £6,500 for a project phase, due on 21 September 2026, under a contract with one company. On 8 October it is unpaid: 17 days late. It went late between 1 July and 31 December 2026, so the rate is 8% over the Bank Rate of 3.75%9: 11.75% a year. That day, accounts ask you to bill a group company instead.
Then it grows by £2.09 a day. The interest and the fixed sum are terms of the contract you signed, so do not assume they follow the invoice to another company. Checking the new company costs nothing and takes ten minutes on the register.
The road ahead
Six steps. Free, unless you hire a lawyer.
Step 1: Find out who signed
Look at the quote, order, purchase order and signed terms for the company name. Then find that company on the Companies House register8 and note its number. A trading name, a website and an email signature are not the legal name.
Step 2: Ask why, in writing
Send the email below to your contact, with accounts copied. A group payments company, a takeover, a project company and a budget held elsewhere are the usual reasons. Do not agree on a call, or in a one-line reply from someone in accounts.
Step 3: Look up the new company
Search the register by name, then compare the company number. Two companies in one group have two numbers, and near-identical names can hide a different company. Check its status, its accounts and how long it has existed: how to check a UK company.
A company formed last month with no accounts filed is a different risk from the group's main company. Signs a company is going under are on the register too.
Step 4: Pick the safest option
Safest first: keep invoicing the company that signed, with the payer's name added as a reference. If they insist, invoice the new company only on a short change signed for both companies, and ask the parent for a written guarantee if the new company is new or thin. If neither suits you, say no, politely, and say why.
A change should name both companies and their numbers, name the invoice it covers, say the payment terms are unchanged, and say whether the first company stays responsible if the second does not pay.
For a large sum, a solicitor who does commercial disputes should read the paper before anyone signs it.
Step 5: Put the right details on the invoice
If the answer is yes, use the new company's exact name, registered address and number, the purchase order number, and a job line such as "for work ordered by [first company]". Keep the payment terms as agreed; if the new company's system pays at 60 days, say in the change that your date stands.
Step 6: Already sent it to the wrong company?
Do not just resend it. Ask the company that signed, in writing, which company is to pay, then issue a credit note and a new invoice if it says so. A letter before action does not go to a company that was invoiced but did not sign.
With no agreed payment date, an invoice is late 30 days after5 the later of the work being done and the customer having notice of the amount3, so a corrected invoice can move the date. An agreed date stands.
A letter you can copy
Email asking for the change in writing
Send it as soon as a client asks you to invoice a different company, before you issue the invoice.
Tap a highlighted gap to see what goes in it.
Send it by email to your contact with accounts copied, so it is dated, and keep the reply with the invoice. A reply from a director, or from whoever signed the order for the first company, counts for more than a one-line answer from accounts.
When not to bother
When it isn't worth it
- It is the same company under a new name. If the register shows one company number, update the name on the invoice and carry on.
- It is a small invoice for a long-standing client with a plainly sound parent. A short written confirmation of the three points is enough; skip the guarantee.
- You are a subcontractor asked to bill the end client. That changes who owes you and carries other risks: see the main contractor hasn't paid me.
- The customer is a consumer. The Act covers only sales between businesses2; consumer rules are different and are not covered here.
The Wolf's note
Inside a group, the contract decides which company owes you, not the name on the invoice. Get the change on paper from the company that signed, with both numbers on it. It costs them one email.
Mr. Wolf · the AI inside WolfX
What comes next
Your next move
If they push back
No written contract: can I still get paid?
Yes. A verbal agreement is a contract.
6 min read · Letter included
If they still won't pay
Can I claim from a director personally for a company's unpaid invoice?
Usually not: a limited company's debts are its own.
7 min read · Letter included
If they go under
The director has started a new company. Can I chase that one?
Usually not: a new company is separate and does not owe the old one's debts.
8 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.