Reader Dave Smith, a newish Apple user, is confounded by Apple ID. He writes:
Not being an Apple person I didn't understand the whys and wherefores of an Apple ID when I bought my first devices. As a result, I have two Apple IDs. One I use for my iPods and iPhone and the other for my iPad. This causes me some grief over time as I sometimes have plugged one in for syncing when the other profile was in place. I'd like to get rid of one and consolidate. Is there any way to do this?
You were doing so well up until you mentioned "consolidate." And there's the rub. Apple does not allow you to consolidate two Apple IDs. A couple of years ago there was some talk of this as an upcoming feature, but it didn't materialize. Rather, Apple embarked on its Family Sharing effort, which isn't the same thing.
So what options do you have? The first thing to do is take a long look at each ID and determine which one is the more necessary. For example, if you've purchased a load of media from the iTunes Store from one ID and not so much from the other, that makes a strong case for abandoning the second one. Note, however, that if we're talking only about music you've purchased from the iTunes Store in the last several years, that's not a problem as music is no longer protected and can be played with either ID. Where it gets sticky is with purchased apps, movies, TV shows, and books. Any free apps you've downloaded from the less-favored account you'll want to download again with the preferred ID.
Then you'll want to think about the data linked to each ID. Where are the majority of your calendar events, contacts, notes, and email? If the account that holds most of your purchased media also holds this data, the argument is over. You know which one to keep.
You'll want to archive any important data from the old account and move it to the new one and you should do this on your computer and then sync the results to your devices. Both Calendar and Contacts let you export data from them, but you have to do it correctly. If you export an entire calendar or contact archive from one account and then attempt to import it to another, you'll be told that you'll replace any existing data with the data held in the archive. This is not something you want to do.
Instead, within Calendars, select a particular calendar and choose to export just it. Repeat for other calendars you have. You can then import them into an existing or new calendar within your keeper account.
Contacts is much the same. Select a group (which can be all of your contacts) and export it as a vCard. Then import the group into the account you're going to hold onto.
Notes are trickier but not impossible. Writeapp's free Notes Exporter lets you export notes as plain text files.
With all the housekeeping done, start your bold new life of using only the keeper account. To help make that possible, after ensuring any data associated with it has been archived and synced with the new account, remove the unwanted ID from your devices.