Check enforceability
Late fees depend on contracts, notice, local rules and customer terms. Do not charge fees that your agreement or law does not allow.
Example
For a 2,000 invoice, a 12% annual late rate and 30 days late, the interest-style fee is about 19.73. With a 25 flat fee, the estimated late fee is 44.73.
Common mistakes
Do not add late fees retroactively if the invoice terms did not disclose them. Also check whether local rules limit rates, flat fees or collection language.
Limitations
This calculator is not legal advice and does not handle compounding, grace periods, partial payments, disputed invoices or country-specific debt collection rules.
Last reviewed: 2026-05-17