1. Click on "Customizable Titles & Texts" in the left-hand navigation:

Transaction Number

To configure invoices number with a prefix, followed by a string of sequential numbers, select “Use a custom format”.

You can insert any prefix for the following transaction number and save the page.

Example of an invoice with the updated prefix:

Instructions on printouts

You can add customized instructions on transaction printouts.

Select the transaction type to customize the instructions.

Enter the instructions in the box and save it.