iTunes Won’t Backup iPhone? Fix Corrupt Backup

You’re plugging your iPhone into your computer. You click Backup in iTunes. And then you see it: “iTunes could not backup the iPhone because the backup was corrupt.” No explanation.

No fix button. Just a dead end.

That error is frustrating because it blocks you from making any new local backups. And if you’re relying on iTunes backups for safety, that’s a real problem. As of 2026, Apple’s official documentation confirms that the only way to resolve a corrupt backup is to delete it and start fresh.

The good news is the fix is simple and takes about 10 minutes. Let’s walk through exactly how to do it.

Quick Answer

Delete the corrupt backup folder. The folder lives in your computer’s MobileSync/Backup directory. Find it by date.

Delete it. Run a fresh backup. That is the only fix Apple provides.

Always rename the folder first before deleting it. This lets you undo the change if something goes wrong.

The Problem: What That “Backup Was Corrupt” Error Actually Means

When iTunes tells you the backup was corrupt, it’s not talking about your iPhone. It’s talking about the backup file sitting on your computer’s hard drive. That file became damaged at some point.

Maybe your iPhone disconnected mid-backup. Maybe your computer shut down unexpectedly. Maybe the file itself suffered a read error.

Whatever the cause, the result is the same. iTunes sees a broken file and refuses to add anything to it. It also refuses to overwrite it. So the backup chain stops dead.

You cannot make a new backup until you remove the damaged one.

This is not a sign that your iPhone is broken. It’s not a sign that your data is lost. The data on your phone is fine.

The problem is on your computer. The corrupt backup file does not hurt your iPhone itself. It only blocks the backup process.

Apple’s support materials confirm that there is no repair tool for a corrupt backup. You cannot patch it. You cannot recover it.

You delete it and start over. That is the only option.

If the backup was encrypted and you forgot the password, the data inside that backup is gone forever. But that’s a separate issue. For the purpose of this fix, you are just removing the file so you can run a new backup.

Before You Do Anything: Know Your Setup (Mac vs. Windows, iTunes vs. Finder)

The steps to find and delete the corrupt backup depend on one thing: what computer you are using. There are four main setups. Pick yours.

If You Are on a Mac Running macOS Catalina or Later

Apple replaced iTunes with Finder starting in macOS Catalina. You do not use iTunes. You use Finder.

• Open Finder.
• Connect your iPhone.
• Select your device under Locations.
• Click “Back Up Now.”

The backup folder path is the same. But the app is different. Do not look for iTunes.

Look for Finder.

If You Are on a Mac Running macOS Mojave or Earlier

You still use iTunes. The process is the same as it always was. Open iTunes, connect the phone, and click “Back Up Now.”

If You Are on a Windows PC

You use iTunes. It is still available on Windows. Apple has not replaced it.

The backup folder lives in a different location than on Mac.

Backup Folder Locations

On Windows, the %APPDATA% variable usually points to C:\Users\[YourUsername]\AppData\Roaming\. So the full path is typically C:\Users\YourName\AppData\Roaming\Apple Computer\MobileSync\Backup\.

On Mac, the ~ symbol means your home folder. The Library folder is hidden by default. You can reach it by opening Finder, clicking “Go” in the menu bar, and selecting “Go to Folder.” Then paste the path.

The Fix: Delete the Corrupt Backup Folder (Step-by-Step)

Here is the process. Follow these steps exactly. Do not skip the rename part.

Step 1: Locate the Backup Folder

Navigate to the correct path for your operating system. Use the table above.

On Mac, press Command + Shift + G in Finder. Paste the path. Press Enter.

On Windows, press Windows Key + R. Type %APPDATA%\Apple Computer\MobileSync\Backup\. Press Enter.

Step 2: Identify the Corrupt Backup

Inside the Backup folder, you will see one or more folders with long names. Those names are alphanumeric strings. Each folder represents a backup for a specific iPhone.

You can identify which one is corrupt by checking the date. On Mac, use List view in Finder. Look at the “Date Modified” column.

On Windows, use Details view. The corrupt backup is usually the most recent one. That is the backup that failed.

If you are unsure, check the size. A backup folder is typically 5 to 50 GB. The corrupt one might be smaller because it failed mid-write.

Step 3: Rename the Folder (Do Not Delete Yet)

Right-click the folder. Choose “Rename.” Add “_OLD” to the end of the folder name. For example, if the folder is named 1234567890abcdef, rename it to 1234567890abcdef_OLD.

This is your safety net. If you rename instead of delete, you can change it back if something goes wrong. If the new backup works, you can later delete the old folder to free up disk space.

Step 4: Run a Fresh Backup

Open iTunes or Finder. Connect your iPhone. Click “Back Up Now.” iTunes should now create a new backup without the error.

The new backup folder will appear in the same location.

Wait for the backup to complete. This can take 30 minutes to several hours depending on how much data you have.

Step 5: Verify the New Backup

After the backup finishes, disconnect your iPhone. Reconnect it. Check that the backup date and time update correctly.

If it shows the new timestamp, the fix worked.

Step 6: Delete the Old Corrupt Backup (Optional)

Once you confirm the new backup is working, you can delete the old folder. Right-click the _OLD folder and move it to Trash. This frees up disk space.

On a 64 GB iPhone, that can be 20 to 30 GB.

What If Deleting the Folder Doesn’t Work? (Decision Branches)

Sometimes deleting the backup folder is not enough. The error might come back. Here is what to try next.

Branch 1: The Error Shows Up Again Immediately

If iTunes gives you the same error right after you delete the folder, the problem is likely not the backup file. It could be your computer’s hard drive.

• Run Disk Utility on Mac. Select your startup disk. Click “First Aid.”
• Run Check Disk (chkdsk) on Windows. Open Command Prompt as Administrator. Type chkdsk C: /f. Restart your computer.
• A bad sector on the drive can cause new backups to corrupt immediately. If the disk check finds errors, back up your data and replace the drive.

Branch 2: The Backup Starts but Fails Partway Through

This means the backup file is being written but getting corrupted mid-write. Possible causes:

• Poor USB cable. Try a different cable. Use an Apple-certified one.
• Old USB port. Try a different port. On a Mac, use a port directly on the computer.
• Interference from antivirus software. Temporarily disable it during the backup. Re-enable it after.

Branch 3: The Error Persists on a Different Computer

If the same iPhone gives the corrupt backup error on a different computer, the problem is on the iPhone. This is rare. Try resetting the iPhone’s network settings or updating to the latest iOS.

If that fails, contact Apple Support.

Branch 4: You Cannot Delete the Folder Because It Is In Use

This happens if iTunes is still running. Close iTunes completely. On Windows, check Task Manager to make sure the iTunes process is ended.

Then try deleting the folder again.

Mistakes to Avoid When Fixing a Corrupt iTunes Backup

A few common mistakes turn a simple fix into a bigger problem. Avoid these.

Deleting the Entire Backup Folder Instead of One Subfolder

The Backup folder contains subfolders. Each subfolder is one backup. If you delete the main Backup folder, you lose all your local backups.

Delete only the one corrupt subfolder.

Forgetting the Encrypted Backup Password

If the backup was encrypted, the folder is still deletable. But the data inside is locked. If you delete the folder and later realize you needed something from that backup, you cannot get it back without the password.

If you have forgotten the password, make absolutely sure you do not need the old backup before deleting it.

Assuming the New Backup Is Automatically Encrypted

If you always used encrypted backups, the new backup will not be encrypted unless you check the box. Go to iTunes or Finder Settings. Enable “Encrypt local backup.” Set a password.

Without encryption, the backup will not include saved passwords, health data, or Wi-Fi settings.

Skipping the Rename Step

Renaming the folder first costs you 10 seconds. It saves you if you accidentally delete the wrong folder. Do not skip it.