9 Easy Ways to Fix SIM Failure on iPhone 2025

Your iPhone needs a working SIM card or eSIM to make calls, send texts, and use mobile data. If you see a “SIM Failure” message, your device won’t connect to the network until the issue is fixed.

Although it’s frustrating, you don’t need to visit a repair shop right away. This guide will explain the common causes of SIM failure and walk you through simple steps to solve the problem. Let’s fix it together and get your iPhone working again.

What Does "SIM Failure" on iPhone Mean?

When your iPhone shows a “SIM Failure” alert, it means there’s an issue with the SIM card - the small chip in your phone that connects you to your carrier’s network. The SIM stores key information that allows you to make calls, send texts, and use mobile data.

This message can appear for several reasons: the SIM card might be dirty or damaged, there could be a software glitch, or your carrier settings might need an update.

Why Does My iPhone Say SIM Failure?

Several factors can lead to a SIM failure on your iPhone. Here are the most common causes:

• SIM Tray Issues: If the SIM tray is damaged or not properly inserted, your iPhone might not detect the SIM card.
• Outdated iOS: Running an older version of iOS can cause compatibility problems with the SIM.
• Software Glitches: Minor bugs, especially after an update, can interfere with SIM card detection.
• Network Problems: A carrier outage or local network issue might trigger a SIM error message.
• Old Carrier Settings: If your carrier settings aren’t up to date, the iPhone may have trouble recognizing the SIM.
• Faulty SIM Card: A scratched, damaged, or locked SIM card can cause the phone to show a SIM failure warning.
• Physical Damage: Drops or water exposure might harm the internal components that read the SIM.

Basic Solutions to SIM Failure Issue on iPhone

If your iPhone has a SIM card but shows messages like “SIM Failure,” “Invalid SIM,” or “No SIM,” try these simple steps to get it working again:

Insert the SIM Card Again

If you're using a physical SIM card, taking it out and putting it back in can often fix SIM failure errors. Use a SIM eject tool or a paperclip to open the SIM tray on the left side of your iPhone. Carefully remove the SIM card, check that it's clean and undamaged, then place it back correctly in the tray and reinsert it into your phone.

Restart Your iPhone

If your iPhone still isn’t detecting the SIM, restart your device. This can help clear out minor software glitches that might be causing the SIM card failure error.

• Press and hold the Power button and either Volume button until the power-off slider appears. For earlier models, just press and hold the Power button.
• Next, slide the power icon to the right to turn off your iPhone. Wait for it to shut down completely.
• Finally, press and hold the Power button again until the Apple logo appears on the screen.

Turn Airplane Mode On and Off

If the SIM error is still showing, try turning Airplane Mode on and off. This helps reset your iPhone’s network connection. Just open Control Center, tap the airplane icon to turn it on (it will turn orange), wait about 30 seconds, then tap it again to turn it off.

Try Using A Different SIM Card

An easy way to find out what's causing the SIM card failure is to try a different SIM card that you know is working. This solution will also let you know if the problem lies on your SIM card or not.

• Obtain a working SIM card by borrowing from a friend, family or relative. You can also just buy a new one if there's no one you can borrow from.
• Remove the SIM card and insert the borrowed SIM card to iPhone.
• If you're still having the SIM card failure issue, it isn't your SIM card causing the problem, but your iPhone.
• If the SIM is working properly, the problem lies on your own SIM card.

Advanced Methods to Fix SIM Failure on iPhone

If the “SIM Failure” message is still showing after the previous steps, try these additional methods to fix the issue.

Check for Carrier Settings Update

If you're experiencing SIM failure and problems with calls, texts, or data, try manually updating your carrier settings. This can often resolve SIM-related issues.

• Go to Settings > General on your iPhone.
• Tap About, then select Carrier.
• If there's an update available, you’ll see a prompt. Just tap Update to install it.

Reset Network Settings

If you still see a “SIM Failure” or “No SIM” message, a software glitch in your network settings might be the cause. A quick fix is to reset network settings. Just note: this will erase saved Wi-Fi passwords, so make sure you know them before you proceed.

• Open Settings on your iPhone and tap General.
• Scroll down and select Transfer or Reset iPhone.
• Tap Reset, then choose Reset Network Settings.
• Enter your iPhone passcode when prompted, then confirm the reset.

Update iPhone to the Latest Version

Sometimes, a SIM failure error can be caused by an outdated version of iOS. Updating your iPhone to the latest iOS version may fix the problem. Follow these steps to check for and install updates:

• Open Settings on your iPhone. Tap General and select Software Update.
• If an update is available, tap Download and Install.
• Follow the on-screen instructions to complete the update.

If there is no update available, it means the iPhone is already up to date.

Using an Effective Tool to Fix iPhone SIM Failure

A faulty iOS system can also lead to SIM failure errors. In this case, using a third-party repair tool may help. One of the top recommendations is FoneGeek iOS System Recovery - a reliable, all-in-one tool designed to fix common iPhone issues like SIM card errors, iPhones stuck on the Apple logo, frozen screens, boot problems, and more. It’s easy to use and doesn’t cause any data loss.

Here's how you can fix your SIM card failure issue using FoneGeek iOS System Recovery.

• Download and install the software from the official site. Launch the app and once prompted with an option, choose Standard Mode.

• Connect your iPhone to your computer and click on the Next option that will be shown to connect your device to your computer.
• The App will automatically search for a compatible firmware for your iPhone. Download the firmware by clicking Download.

• Once you've downloaded the required firmware, you will then be prompted with a Fix Now button to initiate the fixing process of your iPhone.

Your iPhone will restart itself once the Successful message appears. (Can go up to several mintues)

Contact the Wireless Carrier

If you’re still seeing the “SIM Failure” message after trying all the fixes above, it’s time to reach out to your wireless carrier. They can check if your SIM card is still active and if your account is in good standing.

If there’s an Apple Store nearby, you can visit them too. While SIM issues are usually handled by your carrier, Apple Support can help if the problem turns out to be with the iPhone itself.

Conclusion

There's nothing more frustrating than experiencing the SIM card failure on your iPhone. You can't send important text messages, call anyone, and access the internet. Fortunately, there are simple, yet effective solutions that you can try on your own to fix this issue. If troubleshooting it on your own does not work, don't worry, you can still try using a repair tool such as FoneGeek iOS System Recovery to fix any system-related problems that make your SIM fail.