Late Payment Interest Calculator
Calculate the interest owed on a late invoice using UK statutory, EU, US, or a custom rate — based on the amount and the number of days overdue. Includes UK fixed compensation. Free, no signup.
Invoice amount
- Days overdue
- —
- Annual interest rate
- 12.75%
- Interest per day
- —
- Interest accrued
- —
Total now owed—
Uses simple daily interest (amount × annual rate ÷ 365 × days overdue). Statutory rates and fixed compensation vary by country and change over time — confirm the current figures for your jurisdiction before invoicing. This is guidance, not legal advice.
Questions, answered.
- How much interest can I charge on an overdue invoice?
- It depends on your jurisdiction. In the UK, statutory interest on late business payments is the Bank of England base rate plus 8%. The EU late payment directive uses the ECB reference rate plus 8%. In the US, many freelancers charge 1.5% per month (18% a year). Always keep the rate within the legal limit where you operate.
- How is the interest calculated?
- This tool uses simple daily interest: the invoice amount multiplied by the annual rate, divided by 365, times the number of days the invoice is overdue. It doesn't compound, which is the standard approach for statutory late-payment interest.
- What is the UK fixed compensation?
- Under the UK Late Payment of Commercial Debts Act, you can also claim a fixed sum on top of interest: £40 for invoices under £1,000, £70 for £1,000–£9,999.99, and £100 for £10,000 and above. The calculator adds this automatically when the UK basis is selected.
- Can I actually enforce late payment interest?
- You have the right to charge it, but collecting it still depends on the client paying. The most reliable protection is not being owed the money in the first place — for file deliverables, gating the download behind payment removes the late-invoice problem entirely.
Charging interest is a cure. The prevention is getting paid on delivery — FileDue keeps the files locked until the client pays, so the invoice is never late.
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