I just joined Overclockers to post this, as I have spent faaar too much time cost-optimising my phone/data provision and am keen to share.
You can still get O2 Classic 3p/2p/1p (min/SMS/MB) PAYG SIMS on ebay, often for so little that I wonder why the sellers bother given the cost of postage these days. I have two and they have been operating fine for 5wks/3wks. Not only are the rates cheap, but they've also been giving me 30 free minutes every few weeks (to be used within seven days of accepting, with an acceptance window of 4 days) - I don't know how long they will keep doing that. On top of that, I got £5 credit for registering the second one of them with a "My O2" account (or Virgin Media O2 , or whatever it is); I think I didn't get that for the other one because they recognised that email account from a past O2 account.
AIUI, I have to make a chargeable Something every six months.
I had trouble topping up online or using the app, but it was fine over the phone (minimum £10). I don't anticipate topping up again for at least a year.
I haven't ported my regular number to it yet - that should happen on Wednesday. I couldn't work out how to do that online either, but the FB Messenger support person was very helpful (as they have been on several occasions in the past) and set the wheels in motion and I fully expect it to happen.
Sorry if this sounds like an ad, but it's really not - I doubt very much that O2 want people still on tariffs like this any more, given their avaricious nature in other regards.
So I now have those SIMs for phone identities (mobile and "home"), and prepaid Three SIMs for phone data (25GB/mo) and home data (500GB/mo) - works out as under £5/mo all in
