The restriction rule Banking Mandate multi-company, gives an error when editing a partner bank account from a company A when that account has created a mandate from another company B. So it is impossible to create a mandate for each company without disabling the rule.
Solution: Uncheck the rule writte in Banking Mandate multi-company. But i'm not sure this is correct.
* Bug #96 bad use of new API
* [Usability] mandates: search by reference, add group_by, add seq type in tree view
* Add scheme in mandate tree+search view
* Replace tabs by spaces in mandate views
* account_banking_mandate/views/account_banking_mandate_view.xml: convert from dos to unix format
* Add multi-company rule on account.banking.mandate