GJAM Invoice
·6 min read

Late Payment Fees — How to Charge Them (Legally and Politely)

Late fees aren't about the money — they're about behaviour. The threat is the deterrent. Here's how to set them up correctly so they actually work.

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Why late fees work even when you never charge them

An invoice that says 'Net 30 — late payments incur 1.5% per month' gets paid faster than an identical invoice with no late-fee clause. The fee itself rarely needs to be invoked. It's the visible commitment that changes behaviour.

Legal limits by country

  • United Kingdom: Statutory rate is Bank of England base rate + 8% under the Late Payment of Commercial Debts (Interest) Act.
  • United States: Varies by state. 1.5%/month (18% annual) is broadly safe and common.
  • India: 18% per annum is enforceable under the MSME Development Act for small businesses.
  • EU: 8% above ECB reference rate under Directive 2011/7/EU.
  • Australia: 6% above RBA cash rate is the typical max.

When in doubt, 1.5% per month is widely accepted globally and tactful enough to mention up front.

Where to put the late-fee clause

Two places, every time:

  • On the invoice itself — in the Notes section, e.g. 'Late payments incur 1.5% per month after the due date.'
  • In your contract or engagement letter — same wording, signed up front.

Without both, you have a weaker case if you ever need to invoke the fee.

How to actually charge a late fee

Wait at least 14 days past the due date before adding a fee — this filters out simple delays and admin slip-ups.

Send a new invoice with a clear note: "Original invoice INV-2026-007 was due 28 June 2026. The following amount has been added under our agreed late-fee terms: 1.5% × $X = $Y."

Always be polite. The goal is payment, not punishment.

Frequently asked questions

Can I charge a late fee without warning?
Legally risky. The clause should be visible on the invoice (and ideally in your signed contract) before the invoice goes overdue. Without prior notice, courts in most countries will side with the client.
What if my client says 'we never pay late fees'?
Some large companies have policies forbidding them. You have two choices: stick to your terms and risk the relationship, or quietly waive the fee and use the experience to renegotiate Net terms going forward.
Is 1.5% per month too high?
1.5%/month equals 18% annualised, which is broadly accepted globally as a "reasonable commercial rate". Anything above 2%/month starts to feel punitive and may be challenged.

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