Can an account wtih 2 BUs limit use of a short code to only 1 business unit? For example, in my account I have 1 BU for autoparts and 1 BU for auto services. Can I configure MobileConnect to limit selection of this short code to only Users in Autoparts BU, not Services BU?
Are these "BUs" different record types on the Account object? If so, you can set permissions on the approriate profiles so that users only have access to create records with the necessary record type.