The seller has the ticket in their possession.
Seller will dispatch ticket electronically to you (discuss with seller after purchase).
Pay via Credit/Debit Card with PayPal.
AnotherTicket.com is an open trading website.
Purchases are made directly from Buyer to Seller.
Unfortunately I can't go as I now have another engagement!
How to find the O2, London, GB:
If you choose to collect the Ticket from the seller, they are in this approximate location. Delivery options are also available.