If you look at the NetSuite’s SOAP schema browser for Sales Order, you can set custom billing and shipping address using the billingAddress and shippingAddress fields that you see in the schema browser. On the other hand, in Return Authorization schema browser, you can set custom billing address using the billingAddress field, but cannot set custom shipping address, as there is no shippingAddress field or any kind of Address field that represents a shipping address. There is only a shipAddress field in the schema, which is read-only string field.
How do I set custom shipping address for return authorization through NetSuite’s SOAP api?
Here is the NetSuite SOAP schema browser for:
Sales Order - https://system.netsuite.com/help/helpcenter/en_US/srbrowser/Browser2022_1/schema/record/salesorder.html
Return Authorization - https://system.netsuite.com/help/helpcenter/en_US/srbrowser/Browser2022_1/schema/record/returnauthorization.html