No service on new phone

[KatrinaMyers99]

Just upgraded and despite putting replacement sim in, which is the same number, I have no service

[MI5]

@KatrinaMyers99 

You need to use your old sim or start a sim swap from it. 

Guide: Sim Swap: a mini guide 2017 update 

[KatrinaMyers99]

Thank you. However, I was with O2 before, I’ve just upgraded, so I don’t know if that process still works

[MI5 · Accepted solution]

@KatrinaMyers99 

When you upgrade, your new contract is updated on your current sim card, so if it fits the new phone, just use it.

You get a new sim in case the new phone needs a different size sim to your old one, but it is blank so you can use the sim swap process to activate it.

In short, if your old sim fits the new phone, use it.