When you need to change a contact's type, such as changing a Basic Contact to a Client, or a Child to an Adult etc, you will need to:
Archive the old type
Add the new type.
Click on the buttons below to learn more about archiving and adding contact types.
Note on Basic Contact and Basic Group:
If you are changing a contact from Basic -> a type, you do not need to archive the Basic type first. Basic Contact and Basic Group is the default setting, so once you add a new contact type, the Basic label will disappear and be replaced with your contact type
If you are changing a contact from a type -> Basic, you do not need to add a Basic type. You just need to make sure that all types assigned to the contact have been archived. The contact will then default back to a Basic Contact or Basic Group