---
id: help.invoices.numbers
title: "Invoice numbers"
canonical: https://docs.secureprocessing.app/help/invoices/invoice-numbers
description: "An invoice gets its number when you finalise it, such as INV-0001, and each one is the next in your sequence. A number is never skipped or used twice, even if the invoice is voided."
last_verified: 2026-11-02
---

# Invoice numbers

An invoice gets its number when you finalise it, such as INV-0001, and each one is the next in your sequence. A number is never skipped or used twice, even if the invoice is voided.

Who can: Owner, Administrator, Developer, Support can finalise an invoice in [Invoices](https://dashboard.secureprocessing.app/invoices).

## How numbers are given

A draft has no number. Pressing **Finalize** gives it the next one in your sequence: INV-0001, then INV-0002, and so on. After INV-9999 comes INV-10000.

The number is given as part of finalising, so two invoices finalised at once still get two consecutive numbers, and one that fails to finalise gives its number back.

## Never skipped, never reused

A voided invoice keeps its number and stays on record, so your numbers never have a gap that needs explaining. A discarded draft never had one.

## Test mode has its own

Invoices in Test mode are numbered separately from your real ones, so practising does not use up your numbers.

For developers: [Invoicing](https://docs.secureprocessing.app/invoicing.md)

## Related

- [Create and send an invoice](https://docs.secureprocessing.app/help/invoices/create-and-send-an-invoice.md)
- [Void an invoice or write it off](https://docs.secureprocessing.app/help/invoices/void-or-write-off.md)
- [Change an invoice after sending](https://docs.secureprocessing.app/help/invoices/change-an-invoice-after-sending.md)

Still stuck? Write to [admin@secureprocessing.app](mailto:admin@secureprocessing.app) with the invoice’s number.