should not allow to add more than one PY and BP in customer master partner

As per standards, now system allows to add more than one payer and bill-to to any sold-to customer in customer master data partner function data tab.

Now the requirement is:

One sold-to customer should have only one Payer (PY) and one Bill-to (BP) in Partner Functions data tab of customer master and the system should not allow anyone to add more than one PY and BP.

Please help me to solve about issue.

Thanks,

Adikesav