Compliant gap-free invoice numbering

Freelancers and billing teams can prepare a new sequence when upcoming invoices need continuous numbering with no missing entry.

Keep invoice numbering compliant and gap-free by building a continuous series that can be followed across every invoice issued next.

How to use

Enter the prefix for your series, such as the letters that identify your invoices.
Provide the year, the first number in the series and how many invoice numbers you need.
Run the generation to build a continuous sequence of numbers.
Copy the list and check for gaps before adding it to your billing system.

Example

With an input that includes a prefix, a year, a first number and a count, the tool returns an ordered series. Check that the numbers follow each other without interruption and that the prefix and year match your usual format.

Input

INV
2025
1
5

Limits and formats

The tool does not create PDF invoices or fill in legally required invoice details.
It does not verify numbering rules specific to your country or business type.
The generated series is not saved in a history and does not replace your accounting software.
Always confirm the final sequence and format with your accountant or tax authority.

Where processing happens

The number generation runs locally in your browser. The values you enter stay on your device and are not sent to an external service. You can prepare a series without transmitting your invoice information.

Frequently asked questions

Can I continue an existing series?

Yes, enter the first number you want to use for the new sequence. The tool builds the following numbers from that value. Still check that this number has not already been used in your previous register.

Does the tool guarantee legal compliance?

No, it only helps you produce a continuous sequence. Numbering obligations depend on your country and business. Review the applicable rules and have your method validated by a professional.

What if the result has an unexpected format?

Check the prefix, year, first number and invoice count you entered. A space or special character can change the presentation. Correct the input and run the generation again to get the intended series.