The payment terms you set are the single biggest lever you have over whether your invoices get paid on time. Late payment is rarely, at its root, a legal problem. It is a prevention problem. Get your terms, your invoicing habits and your contract wording right at the start, and much late payment never happens at all.
The scale of the problem makes that prevention worth the effort. In July 2025, London Economics published research for the Department for Business and Trade and the Small Business Commissioner. It found that late payments cost the UK economy almost £11 billion a year, and that UK businesses are collectively owed an estimated £26 billion in late payments at any given time. That averages £17,000 per affected business. Late payment hits around 1.5 million UK businesses, 28 per cent of the total, every year. The same research estimates that 14,000 businesses close annually because of it, roughly 38 every single day.
More recent figures come from Bibby Financial Services’ SME Confidence Tracker, published in March 2026. They put the average amount SMEs are currently owed in unpaid invoices at £66,770, up 10 per cent year-on-year. Meanwhile, 62 per cent of SMEs say customers are taking longer to pay in full than they were a year earlier.
Chasing that money is expensive even before you count the cash flow damage. The 2025 research found that 22 per cent of businesses spend staff time chasing late payments, at an average of 86 hours per business every year. That is more than two full working weeks spent chasing money you have already earned, and much of it is avoidable with better terms agreed upfront.
For women running their own businesses, this prevention work carries extra weight. Women founders still launch with less capital behind them on average, and are less likely to have external finance to fall back on, so one unpaid invoice can stall the whole operation.
Choosing the right payment term length
There is no single correct term length. The right choice depends on your cash position, your sector’s norms and your leverage with a particular customer.
- Immediate or payment on order: This suits low-value, one-off work, retail-style transactions, or new customers with no trading history. If you deliver a product or short service and there is nothing to dispute, ask for payment before or on delivery. That removes the risk entirely.
- Seven days: A sensible default for small jobs and repeat freelance work. It also suits customers you trust who still need a short window to process payment through their own systems. Seven days is tight enough to protect your cash flow without feeling unreasonable to most small business customers.
- Fourteen days: Common for project-based work with modest invoice values. It often works as the compromise when a client asks for more than seven days but you are not comfortable stretching to a full month.
- Thirty days: The default many larger organisations expect, particularly corporate clients and the public sector. It is workable if your pricing and cash flow planning account for the delay. Even so, thirty days should be a deliberate decision, not something you drift into because it sounds standard.
A useful rule: the newer the relationship or the smaller the customer, the shorter your terms should be. Reserve thirty days for customers whose scale and payment record justify the wait, and tighten terms whenever you have the option to do so.
Invoice discipline that prevents late payment before it starts
Much late payment is not deliberate non-payment. It is confusion, missing information, or an invoice that sat unopened for a week. Good invoice discipline closes those gaps.
Every invoice should include, without exception:
- A unique invoice number, issued sequentially
- The invoice date and a specific due date, not just a term length
- Your business name, address and contact details, plus the customer’s correct legal entity name
- A clear description of the goods or services, including dates covered for any ongoing work
- The amount due, VAT shown separately if you are VAT-registered, and the total payable
- Your bank details or payment link, and any purchase order or job reference the customer requires
The legal entity point cuts both ways. The name on your own contracts and invoices should match the way you trade. If you have not yet settled your structure, deciding between sole trader and limited company status belongs on the same checklist: it affects your paperwork, tax and liability.
Timing matters as much as content. Send the invoice the same day you deliver the work or hit the agreed milestone. Do not wait until the end of the month to “get round to invoicing”. Every day an invoice sits unsent adds a day to how long you wait to be paid, whatever your contract says about payment terms. For a full breakdown of what belongs on a compliant UK invoice, our guide to writing your first invoice covers the detail.
Build in a light-touch reminder system too. Send a short note a few days before the due date confirming the customer has received the invoice and it is on track. Follow up promptly the day after it becomes overdue. Customers who know you track payment closely are less likely to let your invoice slip to the bottom of the pile.
Stage payments and interim invoicing for longer projects
Waiting until a large project finishes to raise a single invoice is one of the riskiest things you can do. It concentrates all your cash flow exposure into one moment, and it gives a struggling or difficult customer months to find reasons not to pay.
Break longer projects into stages instead, and invoice as each one completes:
- Split work by milestone (design signed off, build complete, final delivery) rather than by arbitrary time periods. That way, each invoice corresponds to something the customer can verify you delivered.
- Invoice as soon as the customer approves a stage, not when the whole project ends.
- Agree the stage structure and the value of each stage in writing before work starts. That avoids renegotiation once you are mid-project.
- For projects running more than a few weeks, add a time-based interim invoice (monthly, for example) alongside milestone invoices. Cash then keeps moving even if a milestone slips through no fault of yours.
Interim invoicing also protects you if a client cancels or disputes work partway through. You have already received payment for the stages you completed, rather than holding all your risk until the final deliverable.
Contract clauses that make your payment terms stick
In UK business-to-business trading, what you write down and agree sets the payment terms, not convention or assumption. Vague wording is therefore one of the most preventable causes of payment disputes. “Payment on receipt” is a classic example: receipt by whom, confirmed how, and from what date? That ambiguity gives a slow-paying customer an easy excuse to stall.
Contracts and terms of business should instead specify:
- An explicit due date, or a clear and unambiguous formula for calculating one. “Within 14 calendar days of the invoice date” works; “promptly” or “on receipt” do not.
- What triggers invoicing, for example delivery, sign-off, or a named milestone. Define it precisely enough that both sides agree when it has happened.
- The accepted payment methods and any reference numbers needed to match your payment correctly.
- What happens if the customer disputes work, so a disagreement over one line item cannot delay payment of the whole invoice.
- Confirmation that your standard payment terms apply to the whole engagement. Reference them in the contract itself. Terms left only on the invoice are easier for a customer to claim they never saw.
Put these terms in writing before work begins, ideally in a signed agreement or a quote the client has accepted. Terms that first appear on your final invoice are far weaker, because the customer can argue they never agreed to them.
One backstop is worth knowing even if you never use it. Under the Late Payment of Commercial Debts (Interest) Act 1998, you can charge statutory interest on overdue business-to-business invoices at 8 per cent plus the Bank of England base rate, plus fixed compensation of between £40 and £100 per invoice. Mentioning that right in your terms often speeds payment on its own. Actually charging it is a last resort; prevention remains the cheaper strategy.
When customers demand longer payment terms than you offered
Larger customers will often push back and ask for 60 or even 90 days instead of your standard 30. This is a negotiation, not a formality. You do not have to accept the first number offered.
A few practical responses:
- Ask why. Sometimes it reflects a genuine internal payment run cycle. Sometimes it is simply the default position they test on every new supplier.
- Offer a trade-off. You could offer a small early payment discount in exchange for shorter terms. Or offer standard terms for the first few invoices until trust is established, extending only once a track record exists.
- Price in the delay. If 60-day terms are non-negotiable and you still want the business, build the cost of the extended cash flow gap into your pricing. Do not absorb it silently.
- Know your walk-away point. If a customer’s required terms would leave you routinely short of cash for your own suppliers, staff or tax bills, the work may not be worth it, however attractive the contract looks on paper.
The same 2025 research found that 15 per cent of businesses have already walked away from customers specifically because of their payment behaviour. You are not being difficult by applying the same judgement; you are protecting the business.
Checking a large customer’s payment record before you agree terms
Before you accept extended payment terms, take advantage of a tool that barely existed a decade ago. The law now requires large UK companies to publish how they actually pay suppliers.
The Reporting on Payment Practices and Performance Regulations 2017 set the first requirement. Large companies must report their payment practices and performance to a government service twice every financial year. From 2025, the Companies (Directors’ Report) (Payment Reporting) Regulations 2025 add a further requirement: large companies must also include payment data in their directors’ reports, putting the data directly alongside their annual accounts.
So before you agree to supply a large customer on their preferred terms, you can look up their actual recent track record. Use the free government service to check when businesses pay invoices. It shows the average time they take to pay invoices and the proportion paid late.
Do this before you sign anything, not after the first invoice goes overdue. Say a customer advertises 30-day terms but their published average payment time is closer to 60 days. They are telling you, in writing, what to actually expect. Use that information to negotiate harder, to build the delay into your cash flow forecasting, or to decide the relationship is not worth the exposure. If slow-paying customers are already straining your cash flow, read our guide to cash flow finance options for small businesses alongside tightening your terms. The two problems usually need solving together.
None of this guarantees every invoice will be paid exactly on time. But small business owners who take these steps prevent the great majority of late payment problems before they start. Set clear term lengths. Invoice promptly and precisely. Break larger projects into stages. Write unambiguous contract clauses. Negotiate extended terms deliberately rather than accepting them by default. Check a large customer’s published record before you agree to anything. The average affected UK business is currently owed tens of thousands of pounds at any one time. Against that backdrop, prevention work pays for itself many times over.
For more on getting paid without friction, see our guide to frictionless payment options for small businesses. And if you are still at the starting line, our step-by-step guide to setting up a business today covers the foundations, including getting your paperwork right from day one.
