Invoice Late Fee Calculator

In most places yes — if your contract or invoice states the late-fee terms before the work began. A common approach is 1.5% per month on the overdue balance, sometimes after a short grace period. Rules vary by region, so confirm what is enforceable where you and your client operate.

A monthly percentage keeps pressure on as the invoice ages and is the most common. A one-time percentage is simpler but stops growing. A flat fee suits small invoices where a percentage would be trivial. Pick one, state it in your terms, and apply it consistently.

A few days of grace (3–7 is typical) shows good faith and covers honest payment delays without souring the relationship. Set it here and the calculator only starts the clock once the grace window has passed.

It drafts a polite but firm chase message with the exact amounts filled in, so you can paste it straight into an email. Staying matter-of-fact and specific gets invoices paid faster than apologising for asking.