I'm a contractor. The agency or end client hasn't paid my invoice. Who owes me?
The short answer
Usually the agency. If an agency supplied you to work for its client, it must pay you for every hour you worked even if the client has not paid it1, and regulation 12 of the Conduct Regulations2 bars it from holding your pay back for that reason, unless your company opted out before the introduction3. An umbrella company that employs you owes your wages. The end client owes you only if you signed with the end client.
England and Wales only. WolfX is software, not a law firm.
What you can add
A £9,000 invoice, 41 days late
Say your company invoiced an agency £9,000 for 20 days at £450, on 31 July 2026. The contract says 14 days, so it fell due on 14 August 2026. The agency said its client had not paid it, then paid you on 24 September 2026: 41 days late. It went late in the second half of 2026, so the rate is 11.75%.
The agency paid the £9,000 that day. The £188.79 of interest and fixed sum is still owed, and you can claim it.
The road ahead
Five steps. All free.
Step 2: Check the agency's role in your contract
An agency that only introduced you is not responsible for paying you1 afterwards, so your claim is under whatever you agreed with the end client. An employment business that supplies you is.
The rules reach a limited company contractor3 unless your company and the person doing the work opted out before the introduction. Where regulation 122 applies, a clause saying you are paid only when the client pays cannot hold your pay back.
Step 3: Work out what is really owed
Between two businesses, a contract for services9 carries interest at 11.75% a year12 on invoices that go late in the second half of 2026, plus £40, £70 or £10011.
If the off-payroll rules apply, the deemed employer must deduct Income Tax and employee National Insurance8 from the fees, so check the sum before you add it up.
Step 4: Email the agency's accounts contact
Send the letter below at about day 14 late, copying whoever signed your contract. Give 14 days to pay and ask for the payment date in writing. Leave the end client out of it unless your contract lets you contact them. The law fixes none of these days.
Step 5: Still unpaid? Complain, then send a letter before action
The Fair Work Agency, the state regulator for employment businesses4, investigates complaints. At about day 30, send a letter before action.
Late umbrella pay is unpaid wages, not an invoice debt. The claim goes to an employment tribunal7, and the time limit there runs from the pay day and is short, so do not wait.
HMRC's guidance on the PAYE rules that changed on 6 April 20266 covers the tax side.
A letter you can copy
Email to the agency: pay now, whatever the client has done
Send it at about day 14 late, once a friendly reminder has not worked and you have checked who your contract is with.
Tap a highlighted gap to see what goes in it.
Send it by email so it is dated, and keep a copy with the invoice and your contract. If your contract says you are paid when the client pays, delete 'and does not make it depend on [Client name] paying you'. If your company opted out before the introduction, delete the regulation 12 sentence. If both, the agency may wait. The examples in the gaps are for a letter sent on 28 August 2026, 14 days late; the sum above is the same invoice on the day it was paid.
When not to bother
When it isn't worth it
- The delay is a few days and the agency is your main source of work. The interest will be small. Weigh it as on the page about charging interest.
- The agency has gone into administration or liquidation. Then you are one creditor in a queue and a chasing letter is the wrong tool. Start with what happens to your invoice.
- Your company opted out of the Regulations before the introduction. Then the Regulations do not apply (regulation 323) and your contract decides whether the agency can wait for its client.
- You are really the client's employee or worker. That is a claim for pay, not for an invoice, and it goes to an employment tribunal7.
- You are in Scotland or Northern Ireland. The route differs, and this page covers England and Wales only.
The Wolf's note
Three email threads, and each says the money is with someone else. Only one party signed your contract: write to that one, quote the clause and ask for a date. The agency and its client can settle their argument between themselves.
Mr. Wolf · the AI inside WolfX
What comes next
Your next move
Put it in writing
What is a letter before action, and how do I write one?
A formal last letter before a court claim, and you can write it yourself.
7 min read · Letter included
On a building job
The main contractor hasn't paid me. Can I go to the client instead?
Usually not: your contract is with the main contractor.
7 min read · Letter included
What you can add
Does the late payment law cover my business and my customer?
Yes, if you and your customer were both acting in the course of a business.
4 min read
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.