Upgrade

[Anonymous]

I've just received my upgrade and done an iCloud back up, do I still need to swap my sim?

[Anonymous]

If the sim you were using won't fit into your new phone then yes.

http://swapmysim.o2.co.uk

Takes from a few minutes to approx 24 hours to settle.

[Anonymous]

Just to touch upon ; The iCloud back up is designed to put all your settings and data onto your new iPhone.

[MI5]

If your sim card is the same size as required by the new phone, just continue to use the same sim card.
The iCloud backup covers all the data on the phone (contacts, texts, apps etc) and is independent of the mobile account which is carried by the sim card data.

[aldaweb · Accepted solution]

If your SIM is 3G and you have the 5S or 5C you will need to swap to a 4G SIM. (it has 3G printed on a 3G SIM or 4G if you already ahve a 4G SIM)

You can get a 4G SIM instore where they can initiate the SIM swap for you, though it can take up to 24 hours I've fopund it normally takes effect within an hour or two. Just turn off the phone and back on periodically to check.