Invoice perm fees on the candidate's start date and ask for payment within 7 or 14 days, or 30 at most. Make the rebate depend on the client paying on time, name the ways a client can pay, and say that late invoices carry statutory interest. For temp clients, invoice weekly and get a direct debit mandate signed with your terms of business.
In this article
The short version
- Invoice perm fees on the candidate's start date.
- Ask for payment within 7 or 14 days, or 30 at most, counted from the invoice date.
- Make any rebate conditional on the fee being paid on time.
- Name how clients can pay, with direct debit for repeat temp clients.
- State that late invoices carry statutory interest at 8% above base rate plus fixed compensation.
When should a perm fee be invoiced?
The fee is earned on the start date, so that's the day the invoice goes out.
Agency terms published by firms such as Reed and Brook Street do exactly this. The fee becomes due when the candidate starts, and the invoice follows straight away. Fees in those terms run from about 15% to 30% of first-year salary, so on a £35,000 role you'd be invoicing about £5,250 to £10,500 in one go.
Waiting until the end of the month to batch perm invoices feels tidy, but it can add weeks to a fee you've already earned. If the start date moves, raise the invoice on the new date. Don't send it early and then credit it.
How many days should clients get to pay?
Pick the shortest term your clients will sign, and write it as a number of days from the invoice date.
Published agency terms ask for 7, 14 or 30 days. Shorter terms put the due date well inside the rebate period, and they give you an earlier date to follow up on. "Payment within 14 days of the invoice date" is clear. "Net monthly" or "payment on receipt" leaves room for argument about when the clock started.
If you never agree a term, the law treats a business invoice as late 30 days after the client receives it. Larger clients sometimes push their own terms of 60 days or more onto agencies. Between businesses, an agreed term over 60 days can be cut back to 60 unless it isn't grossly unfair to you, but in practice the easier route is to negotiate the term before you sign, while you still have the candidates they want.
For temp and contract work, your payroll runs every week whatever the client does, so weekly invoicing on short terms keeps the gap between paying workers and being paid as small as you can make it.
Rebate wording that protects your fee
Your rebate should only apply if the fee was paid on time.
Rebate or guarantee periods commonly run 8 to 12 weeks on a sliding scale, and some run longer. The published terms mentioned above all make the rebate conditional on the client paying within the agreed term. Without that line, a client can sit on your invoice until the candidate leaves and then ask for money back on a fee they never paid.
Spell out three things: the scale (for example, a set percentage refunded for each band of weeks), the notice the client must give if the candidate leaves, and the condition that the fee was paid in full by the due date. Keep the wording in the terms the client signs, and refer to it on the invoice so the accounts team sees it too.
Payment methods and late fees in your terms
Tell clients exactly how they can pay, and what happens if they don't.
A short checklist for the payment section of your terms of business:
- The bank details or payment link the client should use, and that the invoice number goes in the reference.
- Direct debit for repeat temp clients, with the mandate signed alongside the terms, so each weekly invoice is collected on its due date.
- Whether you accept card. Business cards cost more to accept than most other methods, so on a large perm fee you may want to offer card only with a surcharge, or not at all.
- A late payment line: overdue invoices carry statutory interest at 8% above the Bank of England base rate, plus fixed compensation of £40, £70 or £100 depending on the invoice size.
Statutory interest applies to business invoices whether or not you mention it, but if your terms name a different rate, that rate usually replaces it. With the base rate at 3.75%, statutory interest is 11.75% a year. A £7,000 fee paid 30 days late carries £67.60 in interest plus £70 compensation.
Writing the clause tends to be easier than charging it every time, because charging means working out days late and raising a second invoice for a client you'd like to keep. Adfin can add statutory late payment interest to overdue invoices automatically, with the payment link updating as it builds, and you can waive it for a client you want to go easy on. Adfin's Customer Agents can also follow up over email, SMS or WhatsApp within rules you approve, and on bank transfers the fee is 1% + 20p with the percentage capped at £4, so a perm fee paid by bank costs you £4.20 at most.
Common questions
Should perm fees be invoiced on the offer date or the start date? The start date is the common practice in published agency terms, because that's when the fee is earned. Invoicing on the offer date tends to cause disputes if the candidate doesn't start.
What payment terms do large clients usually accept? It varies, and some large hirers push for 60 days or more. Agree the term before you sign and put it in days from the invoice date.
Can I lose my rebate obligation if the client pays late? Only if your terms say so. Make the rebate conditional on payment in full by the due date and keep that wording in the signed terms.
Do I have to mention late payment interest in my terms to charge it? No, statutory interest applies to late business invoices anyway. Mentioning it makes the charge harder to dispute, but naming a different rate can replace the statutory one.
Should temp clients have different payment terms from perm clients? Usually, yes. Temp work suits weekly invoices on short terms, ideally collected by direct debit, while perm fees are one-off invoices raised on the start date.
Can I charge clients a fee for paying by card? You can pass on the cost of a business card payment, but no more than it costs you. Personal cards can't be surcharged.
Sources
- Reed - Employment Agency Terms of Business (accurate as of October 2026) https://resources.reed.com/hubfs/Website/Documents/Terms%20of%20Business/Employment%20Agency%20Terms%20of%20Business%20-%20REED.pdf
- Brook Street - Permanent terms of business (accurate as of October 2026) https://www.brookstreet.co.uk/rails/active_storage/blobs/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBBOHNLUUE9PSIsImV4cCI6bnVsbCwicHVyIjoiYmxvYl9pZCJ9fQ==--aabee74b1bce7842b1e5434e5907452fe14914ef/BrookStreetPermTOBs2022.pdf
- GOV.UK - Late commercial payments: when a payment becomes late (accurate as of October 2026) https://www.gov.uk/late-commercial-payments-interest-debt-recovery/when-a-payment-becomes-late
- GOV.UK - Late commercial payments: charging interest on commercial debt (accurate as of October 2026) https://www.gov.uk/late-commercial-payments-interest-debt-recovery/charging-interest-commercial-debt
