It is highly advisable that we should decide what type of TAX engine we want in our ERP system at the time of implementation .Though Changing a Tax Engine once our Oracle application is already live is not very complex , but we are always running risk of some missing or corrupted data, if we try to play around the Tax related data once Oracle Application is already live.
Reason - with system is already live tax related info like location/rates/exemption rules already stored in Oracle Order Management and Oracle Receivables Transactions.So my advise is decide about all your components before you implement Oracle Applications ( but that is just a advise and not hard fast rule , many a time we have to make tough decision to improve business processes).
I recently has opportunity to work on Project where customer would like to Implement Tax Rates Data from the Vertex and not Oracle Standard rates. This was easy as we were just implementing/changing the Tax Rates and not changing the complete Tax Engine and Setup.
In such a project , following are the required task ( Broad level view).
- Take Back up of Tax related tables ( Rates/Locations)
- Upload the tax Rate file provided by your Tax Vendor in Interface Tables.
- Run the Tax Rates Upload Concurrent Program. It will upload the data in the required Oracle Tax Rates/Loaction base tables and also print the user friendly report about the outcome of the concurrent program.
- Once Step#3 executed Successfully write the validation scripts to validate the
- Postal Code
5.Run the TCA API to update the Location Assignment .
6.Ask your user to Create new location and test if the New tax rates appears as per expectations , also try to update the existing tax records to verify if system behaves as per expectations or not.
7. Create Exemption records /Tax code and verify the outcome.
8.Run End-to-End cycles like Order to Cash and verify the outcome
that's it , above work for me .Feel Free if you have questions