You can buy a PAYG SIM card for as little as £1 in a shop and just fit it into an existing phone. It doesn't matter what type of phone it is; it's the SIM that makes a phone Pay Monthly or PAYG.
To top up a PAYG phone without leaving a paper trail, you go to the phone shop for whichever mobile provider you have chosen, and buy a top-up voucher for cash, rather than with a bank card. You type the voucher number into your phone and that will top up the credit to the amount paid.
All you've then got is the possibility of being seen shopping on cctv.
I know O2 do PAYG SIM cards for free through the post; it would be possible to get one sent to a different address, eg a friend, but it leaves a record with the company.
Hope that makes sense.
Thank you, that makes absolute sense to me.
I just read this article (sorry it is the DM) - but this article surely only refers to circumstances where police have obtained a person's phone??
Police can download your phone's data in minutes with NO warrant | Daily Mail Online
Your explanation covers the events I had in mind. Quite possible to make a purchase in advance that leaves no trail..