Compute late fees and interest on overdue invoices. Deterministic, 100% client-side. Not legal advice — confirm allowable rates in your contract/jurisdiction.
Monthly simple prorates by days/30. Daily simple uses annual%/365 × days. Compounding applies the monthly rate over whole + fractional months.
Small businesses and freelancers frequently face cash flow disruptions caused by delinquent client payments. An invoice late fee and interest calculator helps accurately enforce contract terms by computing overdue penalties. Whether applying a flat administrative fee, simple monthly interest, or compound rates post-grace period, quantifying exact late charges simplifies collections and encourages timely remittance.
No, businesses must adhere to state or national usury laws, which cap the maximum allowable interest rate that can be charged on commercial debts.
Simple interest is calculated only on the original principal invoice amount. Compound interest charges interest on both the principal and any previously accumulated late fees, growing the debt faster.
Generally, yes. In most jurisdictions, you cannot unilaterally impose late fees or interest unless those terms were explicitly agreed upon in a signed contract or terms of service prior to the transaction.
A common commercial standard is 1.5% per month, which equates to an 18% Annual Percentage Rate (APR).