Changing the default contact & contact email / phone is easy!
FROM THE WEB APP
Step 1: Go to the 'Clients' menu > click on a customer to edit.
Step 2: Click on the contact you want to edit
Step 3: Click on the 'Edit' icon on the contact info you want to edit
Step 4: Click the checkbox to set the phone or email as 'Primary'
Step 5: Click the 'Save' button.
Step 6: Done.
FROM THE MOBILE APP
Step 1: Tap on Menu > Clients > Select a specific customer.
Step 2: Tap on the contact you want to edit.
Step 3: Optional: Tap on either 'Name & Preference', 'Phone', or 'Email'.
Step 4: Toggle the 'Make Primary' button.
Step 5: Save.
Next tap on an option to toggle it as the 'Primary' contact method for this contact.