Work out what an overdue invoice should now cost the client. Everything runs in your browser; nothing is sent anywhere.
An estimate, not financial, legal or tax advice.
Charging late fees only works if your contract or invoice states them in advance. See late payment email templates.
Need the invoice template and all 4 escalation emails ready to go? Freelancer Starter Kit.
Scriptable version (same math, flags instead of a form): freelance-late-fee-cli.