Free invoicing tool
Build a clear, consistent invoice-number format and generate your next sequence in seconds.
Generated sequence
Free to use · No signup · Calculations run in your browser
A consistent sequence makes invoices easier to find, reconcile, and discuss with clients. Choose a stable prefix and enough number padding for the volume you expect.
Prefix + optional year + separator + zero-padded sequence number
A prefix of INV, the year 2026, and sequence 42 with four digits produces INV-2026-0042.
Sequential invoice numbers are generally easier to audit and manage. Check the invoicing rules that apply in your jurisdiction.
No. It creates a sequence from the settings you enter, so confirm that the numbers have not already been used in your records.
Payment terms calculator
Calculate an invoice payment due date using Net 15, Net 30, Net 45, Net 60, Net 90, or custom payment terms.
Net payment terms
Add 30 days to an invoice date and find the Net 30 payment deadline instantly. Free calculator with no signup.
Overdue invoice calculator
Calculate late fees, overdue days, interest, and the updated balance for an unpaid invoice using your agreed payment terms.