Using the XML-RPC read method on the res.partner model in a multicompany database, I always get the property_payment_term_id value for the first company.
How can I get the value for the other companies ? The user used to authenticate the XML-RPC call is enabled to access all the companies in the database.
Are you setting using force_company in the context on your call? Please share the code you are using in the future - otherwise readers have to guess how you are doing it and ask questions instead of providing answers.