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Invoice number generator
Pick a numbering format and get a clean sequence of invoice numbers to copy, or paste your last invoice number and get the next one. Consistent numbering keeps your records tidy and your accountant happy.
Next: INV-2026-042, then INV-2026-043
Your format: INV-2026-001
- INV-2026-001
- INV-2026-002
- INV-2026-003
- INV-2026-004
- INV-2026-005
- INV-2026-006
- INV-2026-007
- INV-2026-008
- INV-2026-009
- INV-2026-010
How to number invoices
An invoice number has one job: to identify that invoice, and only that invoice, forever. Three rules cover almost everyone:
- Unique. Never give two invoices the same number, even across clients or years.
- Sequential. Each new invoice gets the next number. Tax authorities in many countries, including the UK and EU member states, expect an unbroken sequence.
- Never reused. If you cancel an invoice, keep its number and issue a credit note rather than deleting it and reusing the number.
Common formats
| Format | Example | Good for |
|---|---|---|
| Plain sequence | INV-001, INV-002 | Most freelancers. Simple and hard to get wrong. |
| Year and sequence | INV-2026-001 | Seeing at a glance which year an invoice belongs to. |
| Year, month and sequence | INV-202609-014 | Higher volumes, and filing by month. |
| Client code and sequence | INV-ACME-007 | Grouping invoices by client. Keep one overall sequence so numbers never repeat. |
Your first invoice number
You don't have to start at 001. Many freelancers start at 100 or 1001 so a new business doesn't look brand new. Whatever you choose, keep counting up from it. If you add the year to your format, starting again at 001 each January is common, because the year keeps every number unique.
Let the numbering take care of itself
The free invoice generator has a number field you can set to any format. A free RivitPay account numbers every new invoice for you in sequence, so you never skip or repeat one.
Frequently asked questions
What is an invoice number?
A unique reference that identifies one invoice. It lets you and your client track payments, match invoices to your records, and refer to a specific invoice without confusion.
How do I choose my first invoice number?
Any starting number works as long as you count up from it. Many freelancers start at 001, 100 or 1001, or use a year-based format like INV-2026-001.
Can I restart invoice numbers each year?
Restarting at 001 each year is common if the year is part of the number, such as INV-2026-001, because every number stays unique. Without the year in the format, keep counting up.
What if I skip or cancel an invoice number?
Don't reuse it. Keep a note of why it was skipped, and cancel a sent invoice with a credit note so your records show an unbroken, explainable sequence.
Can invoice numbers include letters?
Yes. Prefixes like INV or a client code are fine, as long as each full number is unique and your sequence is consistent.