My SIM card will not work in my new phone

[Karenld0]

I have bought a new phone and my old sim is not working in it

[TallTrees]

Does your new phone need a different size? @Karenld0 

Or is it just not connecting 

[Oxonian]

The easiest way to sort out a SIM issue @Karenld0 is to visit your local O2 retail store :-

Store locator | O2 UK | Find Your Nearest O2 Store

https://stores.o2.co.uk/

You will need to take photographic ID with you. 

Otherwise, you can contact O2 by 'phone but your existing SIM card will be disconnected when the new one is issued so you might end up with no working SIM at all for a few days :- 

Guide: How to find help & contact O2 

[MI5]

@Karenld0 

If your old sim still works in the old phone, and it's the same size, there's no reason for it not to work in the new one.

Check you have installed it correctly and adjust the size by popping out the centre if you need to change to a nano sim.