Late Payment Fees & Interest: How Much Can You Legally Charge?

Almost every business eventually reaches the same point: an invoice is weeks past due, the polite reminders have gone unanswered, and you start wondering whether you can add interest to what you are owed. The short answer is yes — but how much, from what date, and whether you even need a clause in your contract depends entirely on where you and your client are based. This guide covers the legal ceilings on late payment fees in the UK, EU, US, Canada and Australia, the exact wording to put on your invoices, the arithmetic behind statutory interest and compensation, and the judgment calls around when charging is worth it.

Quick Answer: How Much Can You Legally Charge?

A late payment fee is interest or a fixed charge added to an overdue invoice to compensate you for being paid late. In the UK and EU, statutory law lets business creditors charge interest at the central bank reference rate plus 8 percentage points plus a fixed recovery cost (£40–£100 or €40), even with no clause in the contract. In the US, there is no federal rate — each state sets a usury cap, and typical enforceable contract rates run 1%–1.5% per month (12%–18% per year). Fees must be agreed in advance in the US, must be a genuine estimate of loss rather than a penalty, and cannot exceed the state cap.

Late Fee, Interest, or Compensation? Three Different Things

The terms get used interchangeably, and that is where most disputes start. They are legally distinct:

• Late payment interest — a percentage that accrues daily or monthly on the unpaid balance until it is settled. It grows with time.
• A fixed late fee — a one-off flat charge (say £25 or $35) triggered once an invoice passes its due date. It does not grow.
• Debt recovery compensation — a statutory fixed sum in the UK and EU that covers your administrative cost of chasing the debt, on top of interest.

Most well-drafted terms use interest as the primary mechanism, because interest is defensible: it mirrors the real economic cost of not having your money. Flat fees are simpler to explain but easier for a client to characterise as a penalty — and penalties are unenforceable in most common-law jurisdictions. If you charge a flat fee, keep it modest and proportional to the invoice value.

A late fee only makes sense once you are clear on when an invoice actually becomes overdue. That is governed by your due date and the payment terms printed on the invoice, not by the date you happened to send it.

United Kingdom: Statutory Interest at Base Rate + 8%

The UK has the most creditor-friendly regime of the major English-speaking markets. Under the Late Payment of Commercial Debts (Interest) Act 1998, as amended, a business selling to another business or to a public authority has an automatic statutory right to interest — no contract clause required.

The headline numbers:

• Interest rate: Bank of England base rate + 8 percentage points, fixed for the six-month period in which the debt became late.
• Fixed compensation: £40 for debts under £1,000; £70 for £1,000–£9,999.99; £100 for £10,000 and above. Charged once per invoice.
• Reasonable recovery costs: If your actual costs of recovery (for example, a debt collection agency) exceed the fixed sum, you can claim the difference.
• Default payment period: 30 days after the later of delivery or receipt of the invoice, if nothing else is agreed. Contract terms longer than 60 days are only valid if they are not "grossly unfair" to the supplier.

Worth noting: statutory interest is simple, not compound, and you can choose to claim it or waive it. You also have six years (five in Scotland) to bring a claim. Full detail is published by GOV.UK.

UK worked example

An invoice of £6,000 is 45 days late. Assume a base rate of 4% — statutory interest is therefore 12%.

Daily interest = £6,000 × 12% ÷ 365 = £1.97
45 days × £1.97 = £88.65 interest
Fixed compensation (debt £1,000–£9,999.99) = £70
Total claimable = £158.65

You can run the same calculation for any amount, term and jurisdiction with our free late payment fee calculator.

European Union: Directive 2011/7/EU

The EU Late Payment Directive harmonises the floor across member states. It applies to commercial transactions between businesses and between businesses and public authorities.

• Interest rate: the reference rate of the relevant central bank (for the euro area, the ECB main refinancing rate) plus at least 8 percentage points. Several member states legislate a higher margin.
• Fixed compensation: a minimum of €40 per invoice, automatically, without a reminder being necessary.
• Payment periods: 30 days as the default; a maximum of 60 days between businesses unless expressly agreed otherwise and not grossly unfair; 30 days for public authorities (60 in limited healthcare cases).
• Non-waivable: contract terms that exclude interest or compensation are void.

Because member states implement the directive locally, the exact reference rate, the compensation amount above the €40 floor, and the procedural steps vary. Check your national implementation before you invoice cross-border. The consolidated text is available from EUR-Lex.

United States: State Usury Caps Decide Everything

There is no federal statutory interest right for commercial invoices in the US. Two consequences follow, and both matter:

1. You need the clause. Without a late fee term agreed before the work — in a contract, signed proposal, or accepted terms of service — you generally have no contractual right to add interest. Printing a fee on the invoice for the first time, after delivery, is weak ground.
2. The rate is capped by state law. Usury statutes limit the maximum rate on contract debt. Commercial transactions are often exempt or subject to a higher ceiling than consumer debt, but the ceiling exists.

In practice, the market convention for B2B invoices is 1% to 1.5% per month, expressed as "1.5% per month (18% per annum) on overdue balances". That range sits inside most state caps and reads as commercially reasonable rather than punitive. A handful of states are materially stricter on the low end, and several allow a much higher rate where the parties are both businesses — confirm your own state, and the client's, before you set a number.

Two further US-specific rules of thumb:

• Do not compound monthly unless your contract says so explicitly. Silent compounding is a common reason fees are struck out.
• A grace period helps you. A stated 5- or 10-day grace window before interest starts makes the term look reasonable and removes the "my payment was one day late" argument.

Canada and Australia

Canada. Section 347 of the Criminal Code makes an effective annual rate above 60% a criminal offence, which is the real outer limit. Below that, commercial parties are broadly free to agree a rate. There is one drafting trap that catches businesses regularly: if you state a monthly or partial-period rate, the Interest Act requires the equivalent annual rate to be disclosed too, or interest may be capped at 5%. Always write "1.5% per month (18% per annum)", never "1.5% per month" alone.

Australia. There is no general statutory interest right for private B2B invoices, so the entitlement comes from your contract. Many businesses anchor their rate to the RBA cash rate plus a margin, and courts will look at whether the charge is a genuine pre-estimate of loss. Government suppliers have separate entitlements under Commonwealth supplier pay-on-time policies. Unfair contract term rules also apply to standard-form small business contracts, so an extreme rate is a real risk.

Late Payment Rules at a Glance

Jurisdiction	Interest right	Typical / statutory rate	Fixed compensation	Clause required?
United Kingdom	Statutory (B2B, B2 public)	BoE base + 8%	£40 / £70 / £100	No
EU member states	Statutory	Central bank reference + 8% minimum	€40 minimum	No
United States	Contractual	1%–1.5% per month, within state usury cap	None (contract only)	Yes
Canada	Contractual	Agreed rate; criminal above 60% effective p.a.	None	Yes
Australia	Contractual	Commonly RBA cash rate + margin	None	Yes

The pattern is clear: in Europe the law does the work for you, and everywhere else your contract does. If you sell internationally, write the clause anyway — it costs nothing in the UK or EU, and it is the only thing that protects you in the US, Canada and Australia.

How to Calculate Late Payment Interest Correctly

Almost all disputes about interest come down to two questions: from which date, and on which balance.

The daily interest method

Daily interest = (Outstanding amount × Annual rate) ÷ 365
Interest owed  = Daily interest × Days overdue

Use the outstanding amount including VAT or sales tax if the tax was invoiced and remains unpaid — you are out of pocket for the whole sum. Count days from the day after the due date, not from the invoice date.

The monthly method

Monthly interest = Outstanding amount × Monthly rate
Interest owed    = Monthly interest × Complete months overdue

Standard in the US. Decide in writing whether partial months are pro-rated or rounded up — "1.5% per month or part thereof" is common but is the harsher reading, so make sure the client agreed to it.

Example: the same invoice under three regimes

A $/£/€10,000 invoice, 60 days overdue:

Scenario	Rate applied	Interest	Fixed sum	Total added
UK statutory (base 4%)	12% p.a.	£197.26	£100	£297.26
EU statutory (ref 2.5%)	10.5% p.a.	€172.60	€40	€212.60
US contract, 1.5%/month	18% p.a.	$300.00	—	$300.00

Two takeaways. First, the sums are meaningful but rarely transformative on a single invoice — the deterrent effect matters far more than the revenue. Second, the fixed compensation in the UK and EU is disproportionately valuable on small invoices: £100 on a £1,500 bill is a real cost to the payer.

Wording That Holds Up: A Late Fee Clause You Can Copy

Put the term in three places — the contract, the quote or proposal, and the invoice footer. Consistency across all three is what makes it enforceable.

Contract clause (adapt the rate to your jurisdiction):

Payment is due within 30 days of the invoice date. Any amount not paid by the due date shall accrue interest at 1.5% per month (18% per annum), calculated daily from the day after the due date until payment is received in full. Where statutory late payment legislation applies, the Supplier reserves the right to claim statutory interest and fixed recovery compensation instead. The Client shall also be liable for reasonable costs of recovery. The Supplier may suspend further work while any invoice remains overdue.

Invoice footer:

Payment terms: Net 30. Overdue balances accrue interest at 1.5% per month (18% per annum) from the day after the due date.

Two supporting habits make the clause work in practice. Get explicit acceptance — a signature, a click-to-accept, or a written "approved" on the proposal — and keep it on file. And make sure your invoices carry an unambiguous due date, a clear invoice number, and the payment terms on the face of the document. The free invoice generator outputs all three by default. If you are still assembling your paperwork, the freelance contract guide covers the surrounding clauses that give the fee its teeth.

Should You Actually Charge? A Decision Framework

Having the right is not the same as exercising it. The question is commercial, not legal.

Charge when

• The client is a repeat late payer and reminders have stopped working.
• The relationship is transactional rather than strategic.
• The client is a larger business paying you late as a matter of policy — in that case the fee is simply pricing the credit you are extending.
• The invoice has crossed 60 days and is heading towards your bad debt provision.

Waive when

• It is a first-time lapse from an otherwise reliable client.
• The delay was caused by something on your side — a wrong PO number, a missing purchase reference, an invoice sent to the wrong address.
• The client has told you about a genuine short-term cash problem and has proposed a payment plan you believe in.

A tactic that works well: state the fee on every reminder, then waive it explicitly when payment lands. "We've applied £70 in recovery compensation, which we're happy to waive if the balance clears this week" converts far better than either silence or an unannounced charge. It uses the fee as leverage rather than as revenue.

Where late payment is systemic rather than occasional, the fee is a symptom-level fix. The structural fixes are earlier invoicing, deposits, and a consistent chase cadence — covered in how to reduce late payments.

Where the Fee Fits in Your Collections Process

A late fee should be the fourth or fifth step in a sequence, never the first contact. A cadence that works for most small businesses:

Timing	Action	Tone
-7 days	Advance courtesy reminder	Neutral, informational
Due date	Payment due today	Neutral
+3 days	First overdue notice	Polite
+7 days	Second notice, fee flagged as pending	Firm but warm
+14 days	Interest applied, restated on a revised statement	Firm
+30 days	Final notice, work suspension, escalation options	Formal

Build this once and let it run. Our reminder schedule builder generates the exact dates for any invoice, and the reminder email generator writes the messages in a polite, neutral or firm tone. For the two hardest steps, we have full templates: the second notice email and the pause-work notice.

Track the outcome, not just the activity. A weekly look at your A/R aging report tells you whether the fee policy is shortening your DSO or simply generating friction.

Six Mistakes That Make a Late Fee Unenforceable

1. Introducing the fee on the invoice only. If the client never agreed to it before the work, it is a unilateral term. Get it into the contract.
2. Setting the rate above the local cap. An excessive rate can void the whole clause, leaving you with nothing rather than a reduced amount.
3. Compounding silently. Charging interest on accrued interest without an explicit contractual right is the fastest route to a struck-out claim.
4. Applying it inconsistently. If you have waived the fee for two years, a client will argue you waived it by course of dealing. Apply the policy uniformly or restate it in writing before you start enforcing it.
5. Charging on a disputed invoice. If the client raised a genuine quality or scope dispute before the due date, resolve the dispute first. Interest on contested work looks aggressive and rarely survives scrutiny.
6. Ignoring consumer rules. Selling to individuals rather than businesses brings a separate and much stricter regime in most countries. The B2B rates in this guide do not transfer.

Bookkeeping and Tax Treatment

Late fee income is ordinary business income in most jurisdictions and is taxable when recognised under your accounting method — on receipt for cash-basis businesses, on invoicing for accrual-basis businesses. Two practical points:

• VAT / GST. Statutory late payment interest and compensation are generally outside the scope of VAT, because they compensate for damage rather than pay for a supply. Contractual interest is usually treated the same way, but a flat "administration fee" for a service can be viewed differently. Confirm with your accountant, and do not add VAT to interest by default.
• Issue it properly. Raise the interest as a separate line on a new document rather than editing the original invoice — the original number should never change. A credit memo is the correct instrument if you later waive the charge.

Related definitions live in the late fee glossary entry and across the wider invoicing glossary.

Frequently Asked Questions

Can I charge a late fee if it is not in my contract?

In the UK and EU, yes — statutory interest and fixed compensation apply to commercial debts automatically, whether or not the contract mentions them. In the US, Canada and Australia, generally no: without a term agreed before the work, you have no contractual right to add interest, though you may still be able to claim interest awarded by a court if you sue for the debt.

What is a reasonable late payment fee?

For B2B invoices, 1% to 1.5% per month (12%–18% per year) is the widely accepted commercial norm. In the UK and EU, statutory interest at the central bank reference rate plus 8 percentage points, plus £40–£100 or €40 in fixed compensation, is the default. Anything materially above these levels risks being treated as an unenforceable penalty.

When does an invoice officially become overdue?

The day after the due date stated on the invoice. If no due date or payment term was agreed, the statutory default in the UK and EU is 30 days after the later of delivery of the goods or services and receipt of the invoice. Interest runs from the day after that date, not from the invoice date.

Can I charge both a flat late fee and interest?

In the UK and EU, yes — statutory fixed compensation sits on top of statutory interest by design. Under a purely contractual regime like the US, you can combine them if the contract says so, but the combined charge must still be a reasonable estimate of your loss. Stacking a large flat fee onto a high interest rate invites a penalty challenge.

Should late payment interest be simple or compound?

Simple interest is safer and is what UK and EU statutory interest uses. Compound interest requires explicit contractual authority in most jurisdictions, and even then may be scrutinised. Unless you have a specific reason and clear wording, calculate simple interest daily on the outstanding principal.

Does a late fee apply to the VAT portion of the invoice?

Yes. Interest is calculated on the full outstanding amount owed, including any VAT or sales tax charged, because that is the cash you have not received — and in many cases have already remitted to the tax authority. Interest itself, however, is usually not subject to VAT.

Will charging late fees damage the client relationship?

Rarely, if it is announced in advance and applied consistently. Clients react badly to surprises, not to policies. Stating the term at proposal stage, restating it on every invoice, and giving one clear warning before applying it keeps the conversation professional. Many businesses find the announced fee is enough on its own — it is collected far less often than it is quoted.

Can I waive a late fee after applying it?

Yes, and it is often the right move. Apply the charge so the client sees the consequence, then offer to waive it in exchange for immediate payment. Document the waiver in writing as a one-off gesture so it does not become an implied variation of your terms.

What if the client disputes the invoice?

Pause the fee and resolve the dispute. Interest on a genuinely contested invoice is hard to defend and escalates a solvable disagreement. Ask for the dispute in writing, agree the undisputed portion, and request payment of that portion immediately — the undisputed amount can still accrue interest if it remains unpaid.

How do I add late fees to a recurring or subscription invoice?

Apply the same clause, but automate the trigger and cap the exposure — for example, suspend service after two failed cycles instead of letting interest accumulate indefinitely. The recurring invoice guide covers dunning sequences for repeat billing.

Is it worth suing for late payment interest alone?

Usually not on its own, but interest and recovery compensation are normally claimed alongside the principal debt in a small claims or county court action, which changes the arithmetic. In the UK, statutory interest plus fixed compensation can add meaningfully to a claim at little extra effort, since no separate agreement needs to be proven.

Putting It Into Practice

Three actions, in order. First, add a late payment clause to your standard contract and quote template using the wording above, with a rate that is valid where your clients are based. Second, print the payment terms and a real due date on every invoice — most late payments start as ambiguity, not refusal. Third, set a reminder cadence and let it run automatically, so the fee is a rule rather than a confrontation.

Start with the late payment fee calculator to see what you are currently entitled to on your oldest unpaid invoice, then use the free tools hub to build the schedule that stops it happening again.

Last reviewed: September 2026. This guide is general information, not legal advice — confirm the rules that apply where you and your client are based.