Backing up your iPhone and iPad to iCloud is critical to keeping your data safe in case of a device failure or loss.But iOS users sometimes receive a disturbing message: "The last backup could not be completed." Here's a look at what might cause this problem, how to fix it, and get your iCloud backups running smoothly again.

These troubleshooting steps apply to iCloud Backup for iPhone, iPad, and iPod touch devices.

How to Fix iCloud Backup Errors in iOS

These troubleshooting steps range from simple fixes to more advanced adjustments, in that order.

1. Restart your device.This is an excellent first step before getting into the other suggestions below, some of which take more time or money to complete.

   See How to Restart an iPad for detailed steps.

2. Make sure iCloud Backup is enabled. Backups won't work if the settings aren't configured correctly. Check it here:Settings>your name >iCloud>iCloud Backup.

3. Connect to Wi-Fi and a power source. Your device runs an automatic iCloud backup but only if it's connected to Wi-Fi and power.

4. Check your iCloud storage. One of the most common reasons for an iCloud backup to fail is because of insufficient free space. Apple includes a small amount of free storage space, but most people require more over time.

   To fix this, either pay for more storage space or delete backed-up items you no longer need.

   To avoid paying for additional storage, consider offloading some of the items, such as photos and videos, to a different free cloud storage service.

5. Make sure your device has enough storage. When an iOS device's local storage is filled to the brim, it has trouble completing basic tasks like backing up to iCloud. If there's not at least 1GB of free space, consider freeing up space.

6. Sign out of iCloud and then sign back in. This can sometimes fix any lingering issues with iCloud. Do this fromSettings>your name>Sign Out.

7. Check the Apple System Status page. If your iCloud backup fails, it might be a problem on Apple's end. On that page, check eachiCloudentry to make sure there aren't any server-side issues. If there are, there's nothing you can do but wait it out.

8. Contact Apple iCloud support. If no other troubleshooting steps solved the iCloud backup error, check out the Apple iCloud support page. It covers a variety of help topics that are delivered through phone, chat, and email support. There's also the iCloud Support Communities where you can submit a question and get help.

   If you prefer in-person help, make an appointment with the Genius Bar at your nearest Apple Store.

Causes of iCloud Backup Errors

A variety of factors can cause iCloud backup errors, including mismatched Apple ID credentials, a poor Wi-Fi connection, not enough iCloud storage, and a lack of physical storage space on the device. Whatever the cause, there are some simple troubleshooting steps to try.