New SIM for upgrade

[loneranger]

hi, I ugraded my plan from 20GB to 25GB. I received a new SIM. When I installed it it said not on Network. I put in the old SIM and it works fine. When I look at my account on line it confirms my upgrade. Can I just keep the old SIM

[Cleoriff]

Hi @loneranger 

Yes, just use old sim. Its all changed on the system not the sim

[loneranger]

Thanks, makes sense. Was just wondering why o2 go to the bother and expense of sending out new SIM.

[Cleoriff]

Some people may want to swap their number @loneranger or the old sim may not fit in a new phone...

Just pop it in a drawer as a spare 

[loneranger]

OK, clears it up, cheers