Best way to have a sim just for a second number and emergency data to switch to

Pescur

Stuart_W said:

Second line option that meets your requirements - 
RWG mobile "buy and forget" 5 year SIM for £15.99. 
You would normally need to make a chargeable call every few months to keep a PAYG account active, this one doesn't need that. The under 27p a month cost gets you 100MB of data each month - so that would nicely cover texts that come in via RCS or whatsapp texts if you don't have other data available. If you top it up you can then do one-off top ups that last for 30 days, £9 for 10GB, £15 for 20GB. No monthly bills involved as it is PAYG. Text a bundle code to 669 and data added instantly (apply the data via text code and not the website - the website isn't instant).

Uses EE signal so depends who primary line is with.

Regularly switching like J_B suggests from one introductory offer to another will certainly be cheaper, if you are not looking to regularly faff about or might miss the end of an introductory period, RWG might be easier. It can certainly fulfil the "one-off data" option. They often run promotions to get double top-up credit which would sit on the account until used. It doesn't expire.

My only concern would be whether they would still be there in 5 years time, they have been around for a but the deal has not been around for as long. Definitely worth a punt at that price.

Stick it in a router as a backup to broadband and as a broadband solution it is far better than a social tariff if you are not a heavy user.

If it is data only is there a way to make wifi calling work in addition to the signal/Telegram/WhatsApp/Facetime or to install as an esim on another phone?

Also to have as an emergency backup sim in the glove compartment of your car.

I can see social providers using these with an appropriate router to give to vulnerable tenants and homeless people.  Just plug in the router at the library or coffee shop and instant wifi on the move.

Thanks for the referral, need a 100 thanks button.

Pescur

Trustpilot score a bit concerning, but mostly about call sims and not arriving sims which is a Royal Mail issue in my experience, some retractions too.