One person can book 2 tickets - you select the day and time you want (make sure that there are enough tickets remaining for that slot to cover the amount you want- many of the slots only had 1 ticket remaining). Then select the amount of tickets (1or 2), I was booking two tickets, so I had to fill in my details of name, email and mobile number, then below this was a section to fill in the same details for the other person you are booking for.That's my question too. I booked two tickets, to be sure, as I panicked about how few slots were left, but potentially I've nabbed a ticket I don't need. So if anyone knows the answer...
Once I had booked - I received an email confirming that I had booked 2 general admission tickets, a PDF was attached with the 2 tickets. The person who you booked for will also receive an email to confirm that a booking has been made for them, it also includes a link for them to retrieve their tickets.
I hope this helps.
We are a family of 4 and obviously wanted to do the tour together- so while I booked for my husband and myself on the iPad, my son at the same time was booking for himself and his sister on his phone. A bit of a long winded way to get 4 tickets for the same time slot- but it worked.