business · free Companion App · local in this browser
Invoice Late Fee Calculator
Calculate a late fee from the invoice amount, rate, and days overdue.
Privacy: This App does not send or save your entries. Do not enter passwords, codes, full account numbers, or private identifiers.
Enter your numbers
Enter only the details needed for this task. Check them against the original source.
Your result
Your result will appear here.
Engine self-test
Running golden cases…
Source notes
- U.S. Small Business Administration — Get Paid on Time: How to Invoice Customers
Clear invoice terms, late fee policies stated upfront, and polite reminders reduce late payment.
Reviewed 2026-10-10. Late fee rules vary by jurisdiction; state your terms in your client agreement.
What this App does not do
This computes from your terms. It does not send invoices or provide legal advice.
This free App has no paid features. It does not contact an agency, employer, bank, seller, provider, or other person.