Invoicing
Invoice Number Generator
Pick a prefix, a year, and how many digits to pad — get a clean, consistent invoice number and a preview of the next few in the sequence.
Next invoice number
INV-2026-001
- +1
- INV-2026-002
- +2
- INV-2026-003
- +3
- INV-2026-004
- +4
- INV-2026-005
Bump the sequence number here every time you send an invoice to keep a consistent, gap-free numbering scheme.
How this calculation works
Format = prefix + year + padded sequence
Your invoice number is built by joining your prefix, year, and a zero-padded sequence number with your chosen separator.
Frequently asked questions
Why does invoice numbering matter?+
A consistent, sequential invoice numbering scheme is expected by accountants and tax authorities in most countries, and it makes it much easier to track which invoices are outstanding, paid, or overdue.
Should I ever skip or reuse an invoice number?+
No — skipping numbers is fine (e.g. for a voided invoice), but reusing a number already assigned to a different invoice can cause accounting and audit problems. Keep the sequence moving forward only.
Once you've picked your format, use it consistently in the Invoice Calculator for every invoice you send.