If you require to set up a "seconded" and/or an "European economic area employee" to your business these are the steps that you will have to take to meet HMRC requirements.
If you go to 'Payroll Settings' > 'Business Settings' and choose 'HMRC Settings' then scroll down the page until you come to 'Additional Options'. The first question will ask "Will you be paying seconded employees?" choose the yes radio button and then scroll down to the bottom of the screen and click on the 'Save' button.
If you now go to the detail page of the employee that you are seconding and under the 'Employee Settings' section click on the 'Tax and NI Details' option.
If you scroll down the page until you arrive at the 'National Insurance Category' option you will see that there is a tick box for a seconded employee. When you place a tick in the box you will notice you now have a drop down menu with 3 options. Choose the option that will apply to the seconded employee. Please also note that there is a tick box for when the seconded employee also qualifies as being a European economic area citizen.
The seconded employee will now be set up correctly for HMRC purposes.