Yes, with some limitations.
After tickets are sold, you are able to:
Edit ticket name— existing buyers will see the new name
Edit ticket price— existing buyers will keep the price they paid
Edit ticket description— existing buyers will see the new description
Increase the total tickets available
Enable / disable tickets at anytime
Disable / enable promo codes
Add check-in staff
After tickets are sold, you are not able to:
Decrease the total tickets available if it is below the number already sold
Delete the purchased ticket type. You can disable it instead, and existing buyers will keep their tickets. If users have purchased tickets from one tier but not another, the un-purchased tier is still able to be deleted
Contact [email protected] with any questions.