Personalization on Invoice workbench for Force Approval option

Hi ,

We have the setup that any Invoice matched to  Order with match option  2 - way (PO) goes for approval as per the AME rules. Invoices which are matched to the Orders with  3- way (receipt) does not require approval.

Business requirement is to chnage setup of number of suppliers from match option from 2 - way to 3- way.

Issue here is there are approx 20K open PO (not billed )for these suppliers which exist in the system. Once the supplier setup is chnaged we are going to have orders with match option 3 way (Receipt).

Its evitable that we cannot avoid invoices from suppliers which will have old PO and new PO's. With currect Invoice approval it goes into error.