IPhone – How to change the iCloud account on the iPhone

No - the iCloud section of the Settings app only allows for one account on iOS 5.

You can however add as many iCloud accounts to the Mail, Contacts, Calendars as you have time to set up. You will see that you can enable the majority of the services on each subsequent non-main iCloud account.

The following items work only on the main account:

• Backup
• Documents & Data
• Photo Stream

The following item is exclusive - any one (but only one) account can have:

• Find My iPhone

For example, I use one iCloud account as my primary personal account and have a second account for a consulting business. Here is what that non-main account looks like when set up.

Back up the 4S (either to your computer or iCloud), then when you set up the 5, select to restore from the old 4S backup. That will restore your iCloud account, and all apps and content.

Once the 5 has been successfully set up with your content, wipe the 4s (Settings → Reset → Erase All Content and Settings) and set it up from scratch, with a new iCloud account for your wife (unless she has an existing one).

It's important to note that your phone account is tied to the SIM card in the phone, so calls and SMSes sent to your existing number will still go to the iPhone 4S, and the iPhone 5 will be linked to your wife's account. To change this, you need to swap the SIM cards, which is easy to do, except the iPhone 4S uses a micro-SIM, whereas the 5 uses a nano-SIM. You're likely going to need to talk with your phone provider to reprogram the SIMs, or get new ones of the proper sizes.