Charges in the Purchase order

Hi All,

I have one scenario in purchase order for charges, actually while invoicing the PO (fully or partially), I want to put the charges tolerance at the time of invoicing the PO and it should based on the invoice amount e.g. if I put the tolerance percentage 10% it should calculate the 10% amount on the invoice amount not the PO amount.

Please suggest whether this can be achieved in the standard AX or required customization.

thanks in advance.