Normal payment terms for a UK marketing supplier, and what the law says when they slip

Payment terms in UK marketing engagements are usually agreed in a sentence and then governed by a statute neither party has read. The statutory position is short, it is published, and one common contract clause switches it off. Here is what is customary, what the law provides, and what to check before you sign, from either side of the invoice.

What is customary in this market

• Monthly retainers billed in advance for the coming month, or within the first few days of it.
• Projects split into milestones, with a deposit on signature, a payment at a defined midpoint and the balance on acceptance.
• Media spend invoiced separately and in advance, because somebody is funding the platform. Never let fees and media sit on one line.
• Payment windows of 30 days from invoice for most private companies, with larger buyers often working to 45 or 60 day internal cycles.

None of that is a rule. The next part is, and it is quoted directly.

The statutory position, quoted from gov.uk

We read the gov.uk guide Late commercial payments, charging interest and debt recovery on 22 October 2026, HTTP 200, using its printable version. Four statements from it matter to a marketing contract.

On the payment date you may agree. 'If you agree a payment date, it must usually be within 30 days for public authorities or 60 days for business transactions. You can agree a longer period than 60 days for business transactions, but it must be fair to both businesses.'

On what happens if you agree nothing. 'If you do not agree a payment date, the law says the payment is late 30 days after either the customer gets the invoice, or you deliver the goods or provide the service, if this is later.'

On the interest. 'The interest you can charge if another business is late paying for goods or a service is statutory interest, this is 8% plus the Bank of England base rate for business to business transactions.'

On the clause that switches it off. 'You cannot claim statutory interest if there is a different rate of interest in a contract.'

That last line is the one to carry into every contract review. A supplier's own late payment clause at a low rate replaces the statutory entitlement rather than adding to it. If you are the supplier, check whether your own template has quietly given away the stronger remedy. If you are the buyer, know that a clause specifying interest is a concession you are receiving rather than one you are giving.

The fixed recovery sums, which are per payment

The same guide sets out a fixed charge for the cost of recovering a late commercial payment, on top of the interest, and states that it may be charged only once for each payment.

The guide adds that a supplier can also claim for reasonable costs each time it tries to recover the debt. Read on 22 October 2026.

The free government service most suppliers never use

The Small Business Commissioner at smallbusinesscommissioner.gov.uk, fetched the same day and returning HTTP 200, publishes a Fair Payment Code, an interest calculator for working out what you can charge on a late invoice, and guidance on unpaid invoices and on negotiating terms. For a small marketing supplier chasing a large client, that calculator turns an awkward conversation into an arithmetic one.

It is also a host the engines read. In our own UK reading of 22 October 2026, described below, smallbusinesscommissioner.gov.uk appeared as a cited source in 2 of the 64 blind readings, and gov.uk in 16 of them.

A measured warning about reading gov.uk guidance

This one cost us twenty minutes and it is worth passing on, because it affects anybody checking these rules themselves. Every chapter URL of that multi page gov.uk guide returns a byte identical document of 72,536 characters containing only chapter one. The interest rate and the recovery sums are not in it. The chapter content is assembled in the browser, so a fetch of the chapter path gives you the first chapter and no error.

The fix is the printable version at the /print path, which served the whole guide at 60,182 characters and is where every quotation above comes from. A page that cites a chapter URL for the 8% figure has either read it in a browser or not read it at all, and anybody building a tool that reads gov.uk guidance should know that the chapter paths are not what they look like.

What our UK reading adds to the payment conversation

On 22 October 2026 we put a 198 question set of British buying questions to ChatGPT and Gemini, with the market fixed inside the prompt because the gl, hl and location parameters on the search API are accepted, return 200 and answer from somewhere else. That gave 64 blind readings, 32 per engine. Government hosts were cited in 16 of them, led by gov.uk at 16 and business.gov.uk at 6, with legislation.gov.uk in 4 and the Small Business Commissioner in 2.

So an assistant answering a British payment terms question is leaning on official sources a good share of the time, which is unusual in this programme's data and reassuring here. What it will not tell you is whether the specific clause in front of you disapplies statutory interest. That requires reading the contract.

What UK buyers and suppliers ask about payment terms

Can we agree 90 days? The guide says a longer period than 60 days may be agreed for business transactions but it must be fair to both businesses. If you are proposing one, expect to justify it, and expect smaller suppliers to price it in.

Does statutory interest apply automatically? It is the position where the contract does not specify a different rate of interest, per the line quoted above. Check the contract before assuming either way.

Should a small supplier actually charge it? Many do not, for relationship reasons, and the useful middle is to state in the contract that you may. A clause you never invoke still changes behaviour.

Is any of this legal advice? No. These are quotations from gov.uk guidance with the date we read them. How they apply to your contract is a question for your solicitor.

What about public sector clients? The guide puts the usual agreed window at 30 days for public authorities and states that you cannot use a lower interest rate in a contract with public authorities. Read it yourself before relying on it.

Three things to do this week if you are owed money

Open the contract and look for an interest rate. If there is one, the statutory 8% over base does not apply and you need to know that before you write to anybody. If there is not, work out what you can charge with the Small Business Commissioner calculator, add the fixed sum for the size of the debt, and send a new invoice for the interest as the gov.uk guide describes.

Then fix the next contract rather than the last one. Define acceptance, state the payment window, and leave the statutory position alone. Those three edits take a morning and they are the difference between chasing an invoice and being paid on one.

For what a British buyer's finance team asks about an overseas supplier, which decides whether your invoice can be processed at all, see our page on a UK entity or an overseas marketing supplier.