If you want to restrict registrants from transferring their tickets to other attendees, you have a couple of option to ensure that the ticket remains under the original person that owns the ticket.
Notes:
The settings below apply only to registrants. This stops registrants from transferring the tickets to another attendee (different email address) through My Registrations. Admins can still transfer tickets to other attendees through the admin console.
They can still edit the other information in the order such as their name and other order form information, but they won't be able to edit the email address. If you do not want them to edit anything, make sure to turn off the toggle to "Allow attendees to edit information" in Registration > Order Form.
If a ticket type is set as non-transferrable and you try to make it transferrable through the order, you may get a confirmation message that it's already transferrable, but the ticket remains non-transferrable, the lock will still appear on the ticket. We are improving this behavior.
Make Ticket Types Non-Transferrable
When this setting is enabled, anyone who has this ticket type cannot transfer their ticket to another user.
Go to Registration > Set Up Tickets
Open the ticket type for editing
Check "This ticket is Non-Transferrable" in advanced settings
Click Save.
Make a Purchased Ticket Non-Transferrable
When this settings is selected, the particular ticket in the order cannot be transferred.
Go to Attendees > Orders
Click the 3 dot menu under Actions
Select Disable ticket transfer
Make the Order Non-Transferrable
When this setting is selected, all the ticket in the order cannot be transferred.
Go to Attendees > Orders
Click the outer 3 dot menu
Select Disable ticket transfer
Non-Transferrable Tickets in the Orders Tab
You will know that a ticket is set as transferrable if there is a lock beside the attendee's name.
If the Order is non-transferrable, the lock will be on the upper left corner above the order number.
Non-Transferrable Tickets in My Registrations
Registrants will know that a ticket cannot be transferred if the Transfer Registration button on the ticket is grayed out.