The
USER_PERMISSION_DENIED error occurs when there is no link between the manager account authenticated in the request and the client account specified in the request headers. Could you perform a
ManagedCustomerService.get() request to determine if the client account is linked to the authenticated manager account? If the client account is indeed linked to the manager account, please provide the complete SOAP request and response logs for the failing request along with the email address used to generate the OAuth2 credentials so I can take a look. Please use
Reply privately to author when responding.
Shwetha, AdWords API Team.