Late payment is the second-most stressful part of running a small business, after taxes. The good news: most late payers are disorganised, not malicious. The right escalation ladder turns 90% of overdue invoices into paid ones without damaging the relationship. This guide is the script and the legal backstop, in the order to use them.
Why clients pay late
Five categories of cause. Disorganised accounts-payable team. Approval workflow stuck somewhere internally. Cash-flow problems they’re not telling you about. Genuine dispute (invoice errors, scope dispute). Deliberate stalling – rare but real. Knowing which it is determines your tactic. Day 1 nudge usually identifies the cause inside 48 hours.
The escalation ladder (5 stages)
The ladder runs as follows. Day 1 after due date:friendly nudge. Day 7: firm reminder, mention statutory interest. Day 14: pause future work, escalate up the client’s chain. Day 30: final demand letter with statutory interest invoiced. Day 45+:solicitor’s letter, county court claim or debt collection.
Stage 1 — the friendly nudge (Day 1)
Email subject: “Quick check: invoice [number] payment”. Polite, no accusation. “Just checking – I see invoice X was due yesterday, did it land OK?”. Often this alone resolves it, because the cause was an accounts-payable miss or an approval queue stalled at someone on holiday. Don’t skip Day 1 to be polite; you’re training the client’s expectations.
Stage 2 — firm reminder (Day 7)
Direct, professional, references the contract terms. Mention statutory interest under the Late Payment Act if relevant. Ask for a specific payment date – not “please pay soon” but “please confirm payment by [date]”. Most disputes that haven’t surfaced by Day 7 will surface here, because a reminder forces the client to either pay or explain.
Stage 3 — pause and escalate (Day 14)
Stop ongoing work and be explicit about it. Email finance directly if you haven’t already. Cc the original contact’s manager if reasonable. Statutory interest is now formally accruing. The pause is the most useful lever a small business has – stopping new work focuses the client’s attention faster than any other action. Most sustained delays end at this stage.
Statutory interest (Late Payment Act)
The Late Payment of Commercial Debts (Interest) Act 1998 (and amendments) gives you a statutory right, for B2B debts, to interest at 8% above Bank of England base rate (around 13% combined as of 2026 – verify current base rate before publishing figures). Plus a flat fee per invoice: £40 for invoices under £1,000; £70 for £1,000–£9,999.99; £100 for £10,000+. Plus reasonable debt-recovery costs. You don’t need to ask for it in advance – it accrues automatically on overdue commercial debts.
Stage 4 — final demand (Day 30)
Formal letter or email titled “Final demand”. Re-attach the original invoice plus a separate statutory-interest invoice. Specify a payment deadline (typically 7 days). State the next step explicitly: solicitor or court action. Keep the tone professional, not threatening – aggressive language can hurt a later court application. Many clients pay at this stage when they wouldn’t at stage 3.
Stage 5 — legal action
Three routes. Money Claim Online via gov.uk for debts under £100,000 – fee starts around £35 and scales with the claim. Most small businesses can file MCOL themselves; for under £10,000 the case goes to the small claims track. Solicitor’s letter – typically £30–£100 per letter and often resolves the issue without further action. Debt recovery agency – takes 10–25% of recovered amount, fast for £500–£5,000 cases. Most £10k+ cases reward a solicitor over a debt collector.
Preventing late payment in future
Clear payment terms in the contract, foregrounded at sign-off (not only in small print). Invoice the day work is delivered. Take 50% upfront on new clients. Direct debit on retainer clients where possible. Track payment history per client – the worst payers reveal themselves quickly, and a 50% upfront premium for slow payers is usually accepted. The simplest preventive change: shorten net terms from net-30 to net-14, which compresses the chase ladder by half.
Frequently asked questions
The questions UK small businesses ask most often about chasing late-paying clients.
How quickly should I chase an overdue invoice?
Day 1 after the due date, with a polite email. Most late payments are accidental — finance team missed it, approval got stuck. A same-day nudge often resolves it without escalation. Waiting two weeks 'to be polite' makes it harder, not easier, to chase.
Can I really charge 8% interest on late payments?
Yes, by statutory right under the Late Payment of Commercial Debts (Interest) Act 1998, for B2B transactions where no contractual interest rate is specified. The rate is 8% above Bank of England base rate. You can also add a fixed compensation sum (£40, £70, or £100 depending on invoice size) plus reasonable debt recovery costs.
Does the Late Payment Act apply to consumer clients?
No, only to business-to-business commercial debts. For B2C, you fall back to your contractual interest rate (if any) and your right to claim general damages. Most small business late-payment scenarios are B2B, so the Act applies.
When should I involve a solicitor?
Once your final demand has gone unanswered after 7-14 days. A solicitor's letter typically costs £30-£100 and resolves a meaningful percentage of disputes. For larger amounts (£10k+) or ongoing disputes, a solicitor's involvement is usually money well spent.
Should I use a debt collection agency?
For smaller amounts (£500-£5,000) where time matters more than the recovery percentage. Debt collectors typically take 10-25% of recovered debt as commission. For larger amounts, a solicitor or Money Claim Online is usually more cost-effective.
What's Money Claim Online and how does it work?
A gov.uk service for issuing claims for unpaid debts under £100,000. Fee starts around £35 and scales with the claim amount. The process is online, you don't need a solicitor for small amounts. For under £10,000, the case will go to the small claims track, which is designed to be navigated without legal representation.
Can I add late fees to invoices upfront?
Yes, you can write contractual late fees into your terms — they should be reasonable (5-10% of the invoice or a flat fee). If you don't have contractual fees, the statutory rate under the Late Payment Act applies automatically. The two are mutually exclusive — either your contractual rate, or the statutory one.
A client keeps paying late but pays in full — is it worth chasing?
Yes, even if the relationship is otherwise fine. A pattern of late payment indicates their cash flow or accounts-payable process is unreliable. Address it directly: 'I've noticed the last three invoices ran 30+ days late. Can we look at the approval process so it doesn't keep happening?' Most clients respond well to a constructive raise of the issue.
