Tickets booked through unofficial agents and listings on sites like Gumtree, could be fake, stolen or invalid. You can’t get into an event with one of those tickets. Here are some handy hints to help you decide if your ticket is valid:
check that the event is happening. If it’s not on The O2 or AXS websites, the tickets are fake
check the face value of the seat on The O2 or AXS websites. Unofficial agents often charge much more and add on huge booking fees
an official ticket agent should be able to give you your block, row and seat details. They should also be able to post your tickets or arrange for you to collect them from The O2 box office
always buy tickets from an official ticket agent. And never buy tickets from anyone outside the venue. These tickets may not be valid and you won’t be able to get in.