Invoice number generator
Choose a format, type the next number you need, and this lists the invoice numbers that follow it — one or a hundred — ready to copy. It runs in your browser: nothing is sent anywhere, and nothing is saved, so it will not remember where you got to.
- 2026-0001
- 2026-0002
- 2026-0003
- 2026-0004
- 2026-0005
- 2026-0006
- 2026-0007
- 2026-0008
- 2026-0009
- 2026-0010
Choosing a format
An invoice number has two jobs: to find one invoice among hundreds, and to make a missing one obvious. The four formats here do the first equally well. They differ on the second, and that is the part worth choosing on.
| Format | Looks like | Best for | Watch for |
|---|---|---|---|
| Sequential | 1001, 1002 or INV-1001 | Anyone. The simplest sequence there is, and it never restarts. | Nothing much. A prefix is optional; keep it the same forever if you use one. |
| Year first | 2026-0042 | Seeing the year at a glance, and a clean restart each January. | Use enough digits for a busy year; four covers 9,999 invoices. |
| Customer code | SMITH-001 | A few regular commercial customers who each want their own run. | Gaps across the business become invisible, and codes clash when two customers share a name. |
| Date-based | 20261103-01 | Seeing the invoice date in the number itself. | The counter restarts every day, so a missing invoice does not show; the date alone collides on a two-invoice day. |
If you have no reason to pick otherwise, use sequential or year first. The other two are here because an accountant or a large customer sometimes asks for them, and if that is you, the generator makes them properly. The invoice numbering guide goes further into why gaps matter, what to do with a cancelled invoice, and how to carry the sequence on when you change software.
How to use the list
- Starting fresh: pick a format and a first number — 1001, or 1 with the year in front — and use them in order.
- Carrying on: type the number after the last invoice you sent, so the new ones continue the old run rather than starting a second one.
- Pre-printed or carbon books: generate the whole run at once and copy it into a spreadsheet or print it, so every page has its number before it is used.
- Minimum digits only changes how the number looks — 0042 rather than 42 — so the list sorts properly in a folder or a spreadsheet. A number that outgrows the padding keeps going (9999, then 10000) rather than wrapping round.
Prefixes and customer codes are cleaned in the list: spaces and most symbols are dropped, and customer codes go to capitals, because an invoice number ends up in file names, bank references and other people’s accounting systems, and most of those choke on anything else.
If you make your invoices here, the numbering is done for you
JobPaperwork’s editor numbers every paper it makes, and each kind has its own series: invoices run #1043, #1044 and on; estimates #E-209, #E-210; receipts #R-501, and so on for quotes, work orders and the rest. A new paper takes the next number in its series, so you never have to remember where you were, and an estimate can never be mistaken for an invoice.
The editor does not let you choose a different format or type your own number, so this generator is for invoices you keep somewhere else — a paper book, a spreadsheet, or other software. To try the editor instead, the invoice templates open with your trade’s usual jobs already listed, and the number is on the paper before you start typing.
Working out terms as well? The Net 30 calculator turns the invoice date and terms into the date the invoice is due.
Questions about invoice numbers
What is a good invoice number format for a small business?
For most one-person businesses, either a plain running number (1001, 1002, 1003) or the year followed by a running number (2026-0001, 2026-0002). Both make a missing invoice obvious, both sort correctly, and both are easy to read out over the phone. Pick one and keep it; consistency matters more than which.
Can I start my invoice numbers at something other than 1?
Yes. Many businesses start at 1001 or 100 so the first invoice does not read as the first. What matters is that each number after it follows on without gaps. If you are moving from a paper book or other software, start at the number after the last one you issued.
Does this generator keep track of which numbers I have used?
No. It lists numbers from the starting point you give it and forgets them when you close the page. Keep track of the last number you used wherever your invoices live. If you make your invoices on this site, the editor does that for you.
Should the invoice number include the customer’s name?
Usually not as your only sequence. A customer code makes each customer’s invoices easy to find, but it splits your numbering into many short runs, so a missing invoice is hard to spot across the business. If you want both, keep a plain running number and put the customer code alongside it as a reference.