Additional payments can be recorded against a staff members contract.
NOTE
You will need to have the Human Resources (HR) user role in order to make these changes
To do this locate the staff's profile by going to Admin > Personnel > Staff and select the staff member in question.
On the profile click the cog next to the contract you need to record this against.
Scroll to the very bottom and beneath the delete contract option you'll see the area to record the additional payment.
Fill out the information and click add payment.
Once this is added it will show on the left of the contract information.
PLEASE NOTE
You cannot edit the additional payments when added therefore if you need to amend this you would delete the record using the little red cross and re add the payment.