Trip Provision to use - If employees can choose Receipts or Per Diem

Hi,

Am aware that SAP has provided 3 trip provision variants. (10 , 80 and 81).

10 is payment by recipts only

80 - M and IE per diems and not on the basis of receipts.

I have a scenario where the employee can CHOOSE hoeo they are reimbursed i.e. by Per Diem or by reciepts ( of course which ever stands out to be beneficial for them 😊 ).

In this scenario which trip provision variant should I use?

regards

Raj