# Set document number prefixes

Choose the prefixes on new invoices, bills, payments and journals.

Canonical: https://demo.qixcount.com/help/setup/document-numbers

Who can do this: Owners, or people with *Manage business settings, roles & permissions*

Where: Settings, then Accounting setup

Document prefixes help you recognize a reference in a list or search result. The settings apply to new numbers; existing documents keep their references.

## Change a prefix

1. Open **Settings**.
2. Select **Accounting setup**.
3. Find **Document numbers**.
4. Enter the prefix for **Invoices**, **Bills**, **Payments** or **Journals**.
5. Select **Save changes**.

Each prefix must begin with an uppercase letter. It may contain uppercase letters, digits and hyphens after that first letter, up to 10 characters in total. A blank prefix is not accepted.

![Document prefix fields and the next invoice reference](https://demo.qixcount.com/images/help/setup-document-numbers.webp)

The next invoice reference is displayed below the fields. It reflects the saved prefix when the page loads. It is a preview of a generated reference, not a reservation that guarantees another person cannot create an invoice first.

## What happens next

QixCount generates later references using the saved prefix and its numbering sequence. This page does not offer a field to reset the sequence or renumber existing documents. If you change a prefix, existing records retain the references already assigned to them.

Continue to [Set a backdating limit](https://demo.qixcount.com/help/setup/prevent-backdating) to review posting dates, or [Design your invoice documents](https://demo.qixcount.com/help/setup/invoice-design-and-content) to change appearance and default wording.

## Good to know

You need the Manage business settings, roles & permissions permission.