Thanks for the useful tips guys

Soz for not getting back sooner but life got in my way...
So basically with 3 if you’re not on a One Plan, (which I’m not), you can get an ‘add on’ for tethering which will cost an extra £5 per month. This is for just 1 Gb; anything over that and you get stung.
My friend was using a Huaweaiuei mobile modem thingy and buys a 3 Gb for 3 months at £12 but, thanks to my questioning, he’s found out that deal isn’t available at that price anymore. The cheapest is now £19 per month unless you buy a whole year’s worth!
Basically, the price of getting on-line is becoming silly. I think, on reflection, I’ll say ball-locks to it and just do everything on my mobile with the all inclusive monthly plan I have for that. I’ve got the AVG for mobile phones app installed; if that’s enough for banking security... (Is anything these days?).