Handset for SMS

[asimon]

I need to receive SMS via wifi calling at home as the network signal where I live is useless. I don't need any other facilities such as data or voice calls as this will be used solely for receiving OTP's at home. I plan to get a PAYG sim for it.  Any suggestions for a cheap handset? I've been looking at older 2nd hand phones for under £40 but it is a nightmare trying to work out whether they can work with wifi calling or which operating systems they will need to run it and even whether they can be upgraded to a recentenough OS or not.

Any suggestions please?

[BandOfBrothers]

I always look at the spec sheets on gsmarena.com which can help @asimon as well as tech sites and YouTube to gain as much information on a phone as possible. 

And for Samsung I use sammobile.com 

[AnnS]

With any PAYG SIM card it needs to be kept active with outgoing activity @asimon , that means making a chargeable activity and adding some credit, preferably at 90 day intervals to avoid disconnection.

Take a look at device guides here: Device Guides