In the VA02 we have the option of changing partner functions. E.g. in Customer master SP is 101, SH is 101, BP is 101 and PY is also 101. No other SH is maintained.
In Sales Order, customer 101 will be coming by default for all the partner functions. Now SH is changed from 101 to 102, system will allow (because it is std functionality) even if 102 is not maintained in the customer master of 101.
But we want that system should allow only those partners which are maintained in the Customer Master of Sold-to party. How can we achieve it? Pl suggests.