NI Category Change

NI Category C

There is a problem using the Historical NI changes wizard where the new NI category is category C.

This is because a negative employee’s NI is generated in the current period against category C, and this cannot be returned as part of the FPS

So we suggest until such time as the logic of the wizard is altered you will have to go back to the old manual process for such changes


  1. Leave the employee on the ‘old’ NI category
  2. Calculate the changes required to the employee’s and employers NI.
  3. This link will take you to the HMRC NI calculator for 2013-2014 –
  4. Enter the changes into the ‘Tax and NI Override’ screen (HR Record > Payroll Functions menu)
  5. The employee’s NI this month will then make those changes to the C category.
  6. After period end change the NI category to the new value