This process is done via the API
Create a customer with a contact via the API and store the ClientId on local system
Update the contact using the ClientId but not the ContactId. A new Primary contact is created and the Old primary contact becomes an “extra contact”.
If then try to update the primary contact with the same email address as the ”extra contact” it says success however does not update the primary contact nor gives an error message. (This is probably because Client Contacts cannot have the same email address).
This issue means the user thinks the primary contact email address on quickfile has been updated when it has not. Invoice emails will then get sent to the wrong email address.
Would be helpful if the DefaultContactId and the AdditionalContactsIds are returned when a customer is created or searched and to have an error message if someone inadvertantly tries to create a second contact with the same email.