To define the auto-generated ID patterns of the transactions:
1. From the top menu bar click Settings.
2. Select Setup/Configuration
3. In the Document Numbers section, enter the desired Prefix, Next Number and Suffix for Sales Invoice and Sales Invoice Payment.
Prefix: The prefix part of the next transaction ID number
Next No.: The serial number (to be used between the prefix and suffix) for the next transaction ID number.
Suffix: The suffix part of the next transaction ID number