Can I simply transfer my existing SIM card to my new phone having upgraded a SIM only deal

[DJT]

I previously had a pay monthly deal with O2 with an iPhone

I was due an upgrade

I bought a new iPhone from Apple and upgraded my O2 deal to a SIM only

I kept the same number and the deal has been activated by O2

Can I simply transfer my existing SIM card from my old iPhone to my new iPhone or do I need to use and activate the new SIM that O2 are sending me?

I don't know why I'm getting a new SIM card if they both use nano SIMs and the number stays the same?

[Bambino · Accepted solution]

@DJT Just use your old sim. There should be no problem.

[MI5]

@DJT 

The new sim they are sending you will be a 5g sim.

Your current sim may not be, so if you are in a 5g area, you can do a sim swap to activate the new 5g sim Guide: Sim Swap: a mini guide 2017 update 

[DJT]

awesome good advice thanks 

[MI5]

You're welcome and enjoy your new phone