Autopopulate Third Party and Legal Entity Tax Registration Numbers in AR Transactions

Summary:

Our client has a business requirement related to the AR Transaction creation process.

Currently, when a user creates an AR Transaction, the following fields are manually selected:

Third Party Tax Registration Number in the Customer tab

Tax Registration Number (Legal Entity) in the Miscellaneous tab

The business requirement is to have both the Third Party Tax Registration Number and the Legal Entity Tax Registration Number automatically populated during AR transaction creation, based on the existing customer and legal entity setup. 

Kindly review the requirement and advise on the feasible approach or configuration/customization options available to enable this auto-population in the AR Transaction screen.