icloud backup fails with 80% available capacity

I turned off Photos, Messages & Mail and storage is only 1 GB (20%). I backup our iphones & ipad on my imac so I deleted the last icloud backup by turning off backup on my iphone. When I restarted icloud backups it STILL WON'T WORK! I just want our iphones & ipad to synch so we see our email & messages on all devices. Is the 5GB a myth? What else do I have to do?

iPhone 16 Pro Max, iOS 26

Posted on Sep 21, 2025 11:35 AM

Reply
5 replies

Oct 2, 2025 11:33 AM in response to hank3737

hank3737 wrote:

I just recently learned that messages can sync across devices without icloud.

Well … sort of … given the right credentials. Deleting messages on one device will not delete them on other devices.


Today my iphone says I don't have enough storage to back up 167MB of 5GB!

You specifically tried to create an iCloud backup? Regardless, such a message might occur if you lack free storage on your device itself. Check Settings > General > [iPhone/iPad] Storage and be certain you have no less than 6GB free at all times.

Oct 2, 2025 8:16 AM in response to sberman

The way icloud works has been confusing. I just recently learned that messages can sync across devices without icloud. I don't back up on my imac to duplicate backups - I just don't trust icloud to work. I also recently learned that the iphone doesn't really let you manage icloud. I had been turning off more and more items but nothing was helping. I had to log in online before I was finally able to delete an old backup that looked like the real undisclosed reason that backing up 1.2 GB kept failing even though we have 5GB of storage. Today my iphone says I don't have enough storage to back up 167MB of 5GB! Very frustrating. We do have our own separate Apple Accounts.

Sep 21, 2025 3:19 PM in response to hank3737

Your post is very confusing. Here is why.

  • “I just want our iphones & ipad to synch so we see our email & messages on all devices.”
    • Seeing email and messages on all your devices has nothing to do with iCloud backup. It requires housing this data in iCloud. Backups are used to restore data in the event of a catastrophe or replacing a device.
    • The use of “our” in your sentence is alarming. An Apple Account should be used by one person. Each person, regardless of age, requires their own Apple Account. Make sure that each family member has a unique Apple Account - Apple Support
  • “I backup our iphones & ipad on my imac”
    • It’s OK, but uncommon, to back up your devices both on a computer and iCloud. I guess that’s a way to be extra careful.
    • The use of “our” raises the red flag noted above.

icloud backup fails with 80% available capacity

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