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Invoice Number Generator

Build a repeatable invoice numbering scheme from tokens, preview a batch and validate existing numbers.

Design an invoice number pattern

Example number: —
Next sequence after this batch: —
Validation: —
Tokens are {PREFIX}, {YYYY}, {YY}, {MM}, {DD}, {N} and {CHK}; {N} accepts a padding value like {N:5}.

How to use the Invoice Number Generator

  1. Type a pattern using tokens such as {YYYY}, {MM} and {N:4}.
  2. Set the prefix, reference date, sequence start and padding.
  3. Generate the preview list, copy it, or validate an existing number.

Features

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Frequently Asked Questions

Common questions about the free online invoice number generator.

Type a pattern such as INV-{YYYY}{MM}-{N:4}. The tool replaces the tokens with the date and a padded sequence to build each number.
You can use {PREFIX}, {YYYY}, {YY}, {MM}, {DD}, {N} and {CHK}. The sequence token also accepts a padding value, for example {N:5}.
The sequence follows the start value you set. If you want a yearly restart, set the start value back to one each year and include {YYYY} in the.
A check character is a letter or digit computed from the rest of the number, so a typo in the number is easy to detect later.
The character values are summed, the total is taken modulo thirty six, and the result is written as a digit or a letter from A to Z.
Paste it into the validate box. The tool reports whether the length matches the pattern and, when enabled, whether the check character is correct.
You can preview up to two hundred numbers in one batch and copy the whole list with a single click.
No. Numbers are built in your browser as you type and nothing is saved or uploaded, so nothing leaves your device.
Yes. It is free and unlimited, with no account, no sign-up and no hidden limits on how many numbers you generate.

Last updated: October 10, 2026