When clicking the Change Basic Pay button on an employee's profile you will not be able to select a date that is previous to the latest effective date of the employee's salary.
For example, if the latest salary line for the employee is dated 01/09/2025 you will only be able to select a date starting with 02/09/2025.
If you need to add a salary line previous to this date you will need to do so from the Pay History page:
Search for the employee and go to their profile.
Click Payroll, then Pay.
Click Pay History.
Click Add Payment (Admin - Unrestricted).
Enter the effective date and select the correct salary details.
Click Save.
📌 Note: You will be unable to select a date previous to the employee's start date. This is true for both methods of adding a salary.