Changing Withholding Tax Groups on supplier pay site

Hi

Using 12.1.3 Oracle Payables.

As business is expecting changes into existing withholding tax rates, there would be changes required in withholding tax groups as well.

To apply the changed withholding tax groups to supplier pay sites, is it advisable to change the existing tax group or to create a new pay site and attach the new withholding tax group to that site?

What will be impact if the existing pay site only is updated with new withholding tax group?

Regards

Shanks