If you’re migrating from another payroll system mid-year or an employee is joining mid-year and has a P45 then you’ll want to enter Opening Balances or Year-to-date (YTD) values.

To access these values go to an employee record and select "Opening Balances" from the payroll section on the left panel.

Whilst P45 figures can be entered at any point, the rest of the values must be entered before your first payment to an employee.

This is because when you finalise an employee's first pay run, the resulting values (YTD, plus values from that pay run) are used as the starting point for the next pay run.

You may need to make an adjustment to the NIC table summaries for an employee.
These are used to calculate the NIC due on a pay run and the values are also reported to HMRC on an FPS.

To edit the NIC Table Summaries after you’ve started paying an employee you must have either an open pay run or an un-submitted FPS as this is where the changes will be stored.

Scroll down to the NIC Table Summaries section to edit the NIC Table Summaries used for the employee. Any FPS that have already been submitted won't be modified, only open pay runs and un-submitted (and future) FPS will be updated.