BillGrid

Free tool · Freelance payment laws

Late fee calculator, to the day.

Enter an unpaid invoice and your terms. See every fee they allow and when, what that is as a yearly rate, and the sentence to print on your next invoice so the fee is agreed before it's due.

Calculator

Your terms
Charge , from days overdue, up to % of the invoice.

The terms are the ones BillGrid offers, worked out the way BillGrid works them out.

40 days overdue on Oct 11, 2026, your terms allow $72.00

1.5% a month is about 18% a year. Never charged on earlier fees.

  1. Fee $36.00
  2. Fee $36.00
  3. Next, if still unpaid $36.00
  4. Next, if still unpaid $36.00
  5. Next, if still unpaid $36.00
Put this on your invoice

Invoices unpaid 5 days after the due date incur a late fee of 1.5% of the unpaid balance, and again every 30 days while unpaid, up to 10% of the invoice total, never on earlier fees.

In the US, no law sets a late fee on a business invoice: it's what you and your client agree, before the work, on the contract or the invoice. A fee added later, without warning, is a dispute waiting to happen. States limit interest in different ways and a court can refuse a fee that looks like a penalty, so keep it reasonable. For comparison, the US government pays its own late contractors 4.75% a year from July to December 2026 (Prompt Payment rate).

Where a freelance payment law applies, a client who pays late can owe you up to double through a court or the city, on top of anything you agreed.

In the UK

Between businesses, the law already gives you interest at 8% a year over the Bank of England base rate and a fixed sum of £40, £70 or £100 per invoice, unless your contract sets its own remedy (GOV.UK). The Commercial Payments Bill, now in Parliament, would cap payment terms at 60 days and stop contracts opting out of that interest. Pick GBP above to use the statutory terms.

Questions

Is the fee charged on earlier fees?

Not here and not in BillGrid: each fee is a share of what's unpaid of the work itself, never of earlier fees.

Why does it stop?

At the cap, if your terms have one; the last fee is trimmed to fit. Without a cap, after a year overdue: by then it's a matter for small claims, not another fee.

What does 1.5% a month come to over a year?

About 18%. Fees here are simple, not compounded.