You can stop an iPhone update before it installs, but your options narrow once it has started

If you see an update notification on your iPhone and want to delay it, you can dismiss the notification and keep using your phone. If the update has already begun downloading in the background, you can delete the downloaded files through Settings. Once an update starts installing — when your phone restarts and shows the Apple logo — you cannot stop it; you have to let it finish. The longer you wait to cancel, the fewer choices you have.

The reason this matters for your device security is that updates often patch vulnerabilities that hackers actively exploit. Delaying an update is a real trade-off: you stay in control of when your phone restarts and what changes, but you also stay exposed to known security gaps. Understanding where you are in the update process determines what you can actually do.

Key Takeaways

  • You can dismiss update notifications and prevent downloads by turning off automatic updates in Settings > General > Software Update > Automatic Updates.
  • If an update has downloaded but not installed, you can delete it by going to Settings > General > iPhone Storage and selecting the update file to remove.
  • Once installation begins (your phone restarts and shows the Apple logo), you cannot cancel — the update will complete even if you force restart.
  • Delaying security updates leaves your phone vulnerable to exploits that are already known to attackers, so the longer you wait, the higher your actual risk becomes.

How to stop an update notification before it downloads

When you see the notification asking you to update, tap "Remind Me Later" or straightforward close the notification. This does not delete the update — it just postpones the reminder. Your phone will ask again, usually within a few days.

To prevent your phone from downloading updates automatically in the future, go to Settings > General > Software Update > Automatic Updates. Toggle off "read iOS Updates" and "Install iOS Updates." This stops your phone from downloading and installing without your permission, but you will still see notifications when updates are available. You remain in control of when the read happens.

How to delete an update that has already downloaded

If your phone has downloaded an update but you have not yet restarted to install it, you can remove the downloaded files. Open Settings > General > iPhone Storage. Scroll down until you see an entry for the iOS version number (for example, "iOS 18.2"). Tap it, then tap "Delete Update."

After you delete it, your phone will stop reminding you about that specific update for a while, though Apple will eventually push it again. If you want to prevent future downloads entirely, use the Automatic Updates toggle described above.

What happens if the update has already started installing

Once your iPhone restarts and shows the Apple logo with a progress bar, the installation process has begun and cannot be stopped. Forcing a restart, letting the battery die, or unplugging the power will not cancel the update — it will only interrupt the installation and potentially cause problems. Your phone will resume the update the next time it powers on.

The safest approach is to let the update finish. Most updates take 15 to 30 minutes. Plug your phone into power, connect to Wi-Fi if possible, and wait. Interrupting an in-progress installation can corrupt your system files and force you to restore your phone through a computer, which is far more disruptive than straightforward waiting.

Why delaying updates creates a security gap you should understand

Every iOS update includes patches for security vulnerabilities. Apple publishes security notes alongside each update that describe which vulnerabilities were fixed. Once that information is public, attackers know exactly what to target on phones that have not yet updated.

If you delay an update for weeks or months, you are knowingly running a phone with known security gaps. This does not mean you will be hacked — it depends on whether an attacker targets you specifically — but it does mean you are accepting a measurable risk. The longer you wait, the more time attackers have to develop and deploy exploits against those specific vulnerabilities.

This is different from choosing not to install a feature you dislike. You are choosing to stay vulnerable to attacks that Apple has already documented and fixed. That is a legitimate choice if you have a specific reason (a critical app that breaks with the new version, for example), but it should be a deliberate decision, not an accidental one.

How to check what security fixes are in a pending update

Before you decide to delay an update, you can see what vulnerabilities it addresses. Go to Settings > General > Software Update and look at the update description. It usually lists major security improvements. For more detail, visit Apple's security updates page (support.apple.com/en-us/HT201222), where Apple publishes the full list of vulnerabilities fixed in each iOS version.

If the update fixes a vulnerability that affects how you use your phone — for example, a flaw in the messaging app or the camera — that is a stronger reason to install it sooner rather than later. If the fixes are for features you do not use, the risk is lower, though not zero.

What to do if an update is causing problems on your phone

If you have already installed an update and it is causing crashes, battery drain, or app failures, you cannot roll back to the previous version. iOS does not support downgrading. Your options are to wait for the next update (which often fixes problems introduced by the previous one), contact Apple Support to troubleshoot the specific issue, or restore your phone from a backup made before the update.

Restoring from backup is a last resort because it erases your phone and reinstalls everything. Before you do that, try the simpler steps: restart your phone, clear the cache for the app that is failing (Settings > General > iPhone Storage > [app name] > Offload App, then reinstall it), or check whether the app itself has an update available in the App Store.

Frequently Asked Questions

Can I stop an update that is already installing?

No. Once the installation begins (your phone restarts and shows the Apple logo), you cannot cancel it. Forcing a restart or unplugging power will not stop the update — it will only interrupt the process and potentially cause damage. Let the update finish.

Will my phone update automatically if I do not turn off automatic updates?

Yes. By default, iPhones read and install updates automatically, usually overnight when plugged in and connected to Wi-Fi. If you want to control when updates happen, go to Settings > General > Software Update > Automatic Updates and toggle off both options.

What if I delete a downloaded update and Apple keeps pushing it again?

Apple will re-offer the update periodically. If you want to delay it longer, delete it again. If you want to stop seeing the notification entirely, turn off automatic updates in Settings. You can always install it manually later by going to Settings > General > Software Update.

Is it safe to delay a security update for a few weeks?

It depends on your risk. If you have a specific reason — an app that breaks with the new version, for example — a few weeks is manageable. But the longer you wait, the more time attackers have to exploit known vulnerabilities. If there is no blocking issue, installing within a week or two is the safer choice.

Can I update my iPhone without restarting it?

No. All iOS updates require a restart. Your phone will restart automatically during the installation process. Make sure your phone is plugged in and you have time to wait — do not try to update right before you need to leave.