2g to 4g on pay as you go phone

[Sgd]

I have a pay as you go Doro phone that is 2g and understand I am going to have to get a 4g phone soon, I don't use internet only using  the phone for calls and receiving texts, will I need a new sim or can I use the one in my existing 2g phone,

[jonsie]

You will need a new sim when you upgrade to a 4G phone

However it will be probably a couple of years before 2G is switched off

So there is no hurry to do anything to be honest

[MI5]

@Sgd 

\No need for either a new phone or sim.

You will not be affected until late 2026 (at a guesstimate) when O2 turn off 2g.