Apple’s iCloud service comes with 5 GB of storage for free, with the option to update to larger, paid storage levels. When that storage nears capacity, Apple sends an email warning that the account is running out of space, and suggesting that you either manage your storage settings or increase your storage plan. Should you find yourself in this situation, your iCloud storage can be managed from a Mac or an iOS device (iPhone, iPad, or iPod touch).
From an iOS Device
To manage iCloud storage from an iOS device, tap SETTINGS, then ICLOUD, then STORAGE.
To upgrade to a larger storage plan, tap CHANGE STORAGE PLAN. Otherwise, to manage what is currently saved in your iCloud storage, tap MANAGE STORAGE.
On the Manage Storage screen, you will see device backups, apps using iCloud storage, and Mail usage. Tap a backup to adjust backup settings or delete the backup entirely. Tap an app in the list to view a list of files stored in iCloud by that app. To delete a file, swipe left on the file in the list, then tap DELETE.
Mail usage can only be reduced in your email client by removing emails that are stored on the server.
From a Mac
To manage iCloud storage from a Mac, click the Apple symbol at the left of the menu bar, then choose SYSTEM PREFERENCES. In System Preferences, click ICLOUD.
In the iCloud settings, click MANAGE.
To upgrade to a larger storage plan, click BUY MORE STORAGE. To manage the existing storage, select BACKUPS or an app from the list on the left.
To delete a backup or an app’s file, select it in the list on the right, then click DELETE. To delete all data from a particular app, select the app, then click DELETE DOCUMENTS AND DATA. Keep in mind that deleting an app’s files or data from iCloud will usually remove it entirely from the app as well.
Click DONE when you are finished managing the storage.
Jason Merrill, Mac & iOS Consultant