Below is a Couple's Guide to Sharing an Apple ID.
I've had to explain this same process at least 4 times over the holidays to family so I decided to write a tutorial on how to share an Apple ID within a household. I will do my best to explain it as succinctly and clearly as possible. I will use a made up couple to demonstrate the situation.
Jack and Jane, happily married for 5 years.
In the household they have an iPhone 5s, an iPhone 5, an iPad Mini, and two MacBook Airs.
Jack needs his OWN personal iCloud account. Jane ALSO needs her OWN personal iCloud account.
To confirm that this is the case, we will take Jack's iPhone 5 and go to Settings>iCloud. At the top it will say Account and then show his ID. His happens to be jackrocks4ever@icloud.com.
You will repeat the process on Jane's phone to confirm she also has her own iCloud account. Her iCloud address happens to be janerules4life@gmail.com.
NOTE: An iCloud account can end in @icloud.com, @me.com, @gmail.com, @hotmail.com, etc. It doesn't matter. It is simply whatever account you created when iCloud came out or it is the Apple ID you already were using when iCloud came out. (Also know that @mac.com, @me.com, and @icloud.com are all aliases.)
Jane will log in to iCloud on her Mac and Jack will log in to his iCloud on his Mac. But what about the iPad?
Sharing an iPad doesn't work very well. In my household, my wife is logged into iCloud on the iPad. As a result, the calendars, contacts, and messages are all hers. Sadly there is no way yet to have multiple iCloud accounts on one iOS device.
OK, now lets talk about the part that confuses many people. If you are a couple that doesn't love paying for things twice, I highly recommend that you share an Apple ID for the App Store, iBooks, and iTunes. Doing so will save you a lot of money in the long run.
It doesn't matter which Apple ID you use but pick one and then NEVER change. I'm serious about never. Everything you buy is associated with that Apple ID, so if you buy music, TV shows, movies, and apps, those will forever be associated with that Apple ID.
In the case of Jack and Jane, Jack bought his first iPod in 2007 and created the following Apple ID at that time: Jack1984@gmail.com. He has been buying movies and music ever since. Jane got her first iPhone this fall. So, the family is going to use jack1984@gmail.com for purchases.
Let me repeat: jack1984@gmail.com IS THE APPLE ID THE FAMILY AKA BOTH JANE AND JACK WILL NOW BOTH USE.
So, on Jack's iPhone, we will go to Settings>iTunes and App Store and then confirm that it says Jack1984@gmail.com.
Note: Jack has two separate Apple ID's on his phone. For iCloud he is using jackrocks4ever@icloud.com and for the stores he is using jack1984@gmail.com. Let me just quickly point out that if Jack had purchased his first apple product last year and created his apple ID as jackrocks4ever@icloud.com, he could use that for his apple store purchases as well. It is not a problem that he has a different ID for iCloud than he does for the ID he uses in the stores.
Now, back to Jane's phone. Go to Settings>iTunes and App Store and then NOW PAY ATTENTION, you will want to log in using jack1984@gmail.com. In fact, you are going to make sure that on both computers in the Mac App Store and iTunes, you are logged in to jack1984@gmail.com.
On the iPad, you will also login as jack1984@gmail.com.
So to reiterate, if you are jack and jane, you will forever use jack1984@gmail.com for all purchases regardless of whether or not you are Jack OR Jane.
Now for some FAQ.
Q:I'm Jack and I don't want to tell Jane the password to the Apple ID jack1984@gmail.com. What should I do?
A: If you don't trust Jane with your password, your marriage will probably not work out very well anyway.
Q: I'm Jane and I too have had an Apple ID since 2007. What if I don't want to give up my Apple ID? I've purchased lots of music and apps too.
A: This makes the situation tricky indeed. However, in my opinion, if you plan on being married for the rest of your mortal lives, I think it is best to cut your losses and move forward. Because, in this situation, you only have two options. Either keep your separate ID's and thus keep the barrier between sharing apps, music, movies, books, and TV shows you purchase. Or you give up your Apple ID and start sharing going forward, only having to buy content ONE time.
Q: We both have Apple IDs with purchases? Who should switch over to the other person's Apple ID?
A: Use whichever Apple ID has the most purchases of value associated with it. If Jane has more, use Jane's.
Q: We have a 13 year old. What should we do about their iPod?
A: I have no idea. No, but seriously, that is an age where this decision becomes tough. You may want to cut them off and have them get their own Apple ID. It does, however, make it so they can't share any purchases you buy but it prevents them from knowing your Apple ID password and potentially running up high charges. Granted you could keep your password a secret from the child but at age 13, they are going to want to download snapchat when they want and not wait for you to type in the password for them.
Q: Can't I just log in and out of different Apple IDs in the app store on my iPhone?
A: No, you cannot. You can only change once every 90 days. So make sure you DECIDE definitively before you do make the decision and log out and then log in. http://support.apple.com/kb/ht4627
Q: How many devices can I have associated with one Apple ID?
A: 10. http://support.apple.com/kb/ht4627 So if you happen to be an Apple junky and have LOTS of devices, you are going to run into a pickle eventually.
Q: Is it honest to share?
A: Apple says you can have 10 devices associated with an Apple ID. We would assume that they are saying 10 devices belonging to one person. So, in my family, I believe all the devices "belong to me." Or they could very well all belong "to my wife." So if you believe in this sort of living, where nothing is truly his or hers, then yes, it is honest.
If you have any further questions, swing by an Apple store or ask me for clarification in the comments. Best of luck to you!
Note: If you are wealthy, you may not want to share. If you don't ever plan on buying anything from Apple, you also may not want to share.