iSAMS / Groupcall / ParentPay

[CyBeRkId2002]

Does anyone here sync ParentPay from iSAMS (via Groupcall)???  If so would you be able to provide us with which field it uses as the unique identifier for the pupil?  At present I can see from the API it could be three options:

 

Pupil ID

Person ID

Person GUID

SchoolID

 

I suspect it is SchoolID but want to make 100% certain first as we are going through a mapping exercise (changing MIS) and I am not filled with confidence we have the correct info!  Don't want to be in a position we have 100's (or possibly 1000's) or duplicates!