Type in the event or artist in the search box at the top right-hand side of the screen and from there you'll be able to see when tickets are due to go on sale if they aren't already. International customers, please note that all times listed on the site are UK time.
If you cannot find the event or artist you're looking for, you can sign up for Ticket Alerts in your Ticketmaster account.
For tips on how to improve your chances of making a booking just click here.