Upgraded Regimes versus New Regimes

Hi Everyone -

We are currently in the process of upgrading from 11i to R12.1.3

During our R12 upgrade, we have made a decision to move to New Regimes instead of using the Upgraded Regimes on EB-Tax. We are integrated with Vertex Q Series 3.3 on the O2C side.

However, we still have some design questions open and would appreciate any feedback re the below:

1) What dates should be used to end-date the upgraded regimes and start the new regimes? We have heard differing view points on how this works.

2) For upgraded invoices, which regime will be used for tax calculation if these invoices are credited, or if they are copied ?