UpdateCustomerDTO

Optional. First name of the contact. Omit or null to leave unchanged. Required field: an empty string is rejected (it cannot be cleared).

Optional. Middle name of the contact. Omit or null to leave unchanged; empty string to clear it.

Optional. Last name of the contact. Omit or null to leave unchanged. Required field: an empty string is rejected (it cannot be cleared).

Optional. Business name of a commercial customer/prospect. Omit or null to leave unchanged. Required field for commercial contacts: an empty string is rejected (it cannot be cleared). Applies only to commercial (Type == "C") customers; use FirstName/MiddleName/LastName for personal contacts.

Optional. EmployeeID of the agent to assign. Omit or null to leave unchanged; 0 clears the field; a positive value must be an active employee with access to the customer's office.

Optional. EmployeeID of the CSR to assign. Omit or null to leave unchanged; 0 clears the field; a positive value must be an active employee with access to the customer's office.

Optional. Date of birth as "yyyy-MM-dd". Omit or null to leave unchanged; empty string to clear; a valid date to set.

Optional. One or more addresses to insert or update (any type: Mailing, Billing, Garage, Location). Omit or null (or empty list) to leave addresses unchanged. Per address: AddressID = 0 inserts; a non-zero AddressID updates an existing address that belongs to this customer.