Every booking has a Contact email — the address that booking's communications go to. When the client has more than one address saved on their record, you choose which one this booking uses.
This is useful when the same client books for different reasons. A company trip can go to their work address while a personal trip goes to their personal one, without you editing the client's record between bookings.
Choosing the contact email on a new booking
Click + New Booking.
In the Client card, select the client.
Under Contact email, click the dropdown. It lists every address saved on that client's record, with their main address marked Primary.
Select the address this booking should use. The Primary address is selected by default, so you only need to change it when a different address fits the trip.
Finish building the booking and save as usual.
If the client has only one address on file, there is nothing to choose — that address is the contact email. To add more addresses, see How to Add Multiple Email Addresses to a Client.
What the choice affects
The address you select becomes the destination for that booking's communications going forward — confirmations, invoices, reminders, and other trip messages.
The choice applies to that booking only. It does not change the client's record, and it does not affect their other bookings, which keep whichever contact email was chosen for them.
Changing the contact email later
You can switch a booking to a different one of the client's saved addresses after the booking is created.
Open the booking and click Edit.
In the Client card, open the Contact email dropdown — the same field you see when creating a booking.
Select the address you want, then click Save.
Any messages still scheduled to go out update to the new address, so you don't need to reschedule anything by hand.
This changes which of that client's addresses the booking uses. To move the booking to a different person entirely, see How to Change the Booking Client on a Booking.
Sending a single message somewhere else
Changing the contact email is for the booking as a whole. When you only need one message to land somewhere different, you have two options that leave the booking's contact email untouched:
Pick a different saved address on that individual send.
Send to an alternate address that isn't saved on the client's record at all. See How to Send an Invoice to an Alternate Email Address.