Sign up using the link for the pixel 2 xl on the o2 £30 sim only contract 12 month deal, and as soon as you receive the phone/sim you must cancel the sim within 14 days of receiving it.
Just ring o2, or Vodafone if you take that deal and cancel.
You can do this with countless phones on carphone which is legal.
You can also get £52.50 cashback via topcashback for signing up to this deal.
I did this exact same thing with the p10 lite and received the cashback within 3 weeks. (paying only £89 for that)
You are essentially paying £476.50 for this phone after cashback.
Any questions and I'll answer
I know people will have some.