O2 network

[Nell2]

Are O2 sending letters with replacement SIM cards informing customers that o2s network is changing on the 1st April and to follow the instructions in the letter

[MI5]

@Nell2 

You'll be sent a new sim.

When you receive it, you need to do a sim swap Guide: Sim Swap: a mini guide 2017 update 

I'm only guessing, but I suspect they are turning off 2g in some areas and any old 2g sims won't connect to the extended network.

[Bambino]

@Nell2 It's nothing the community has been informed of. Sounds like a scam. If you receive something in the post, do not do anything without confirming it with O2. Guide: Coronavirus Community Help and Support 

[MI5]

A previous speculative discussion here https://community.o2.co.uk/t5/Discussions-and-Feedback/Future-of-2G/td-p/1122936

[b4u2]

probably a scam. ring customer services and ask them.