Proof of Purchase or ID required on entry?

[Pudso]

Unfortunately I can't attend the festival anymore and need to sell my ticket  I was looking at the official option to do that (Twickets) and it doesn't seem like a very good deal to the buyer, with them charging 10% on top of the ticket value, which is £18 if I list it at face value!
 

If that turns out to be my only option then I'll probably just list it cheaper, but I was wondering what the likelihood of someone being asked for ID/proof of purchase on the gate was if I sold it on Gumtree or something instead, or even just to a friend?

Cheers!

[juliadevitt]

i've been for the last four years but have never been asked when collecting my wristband