Some users have been seeing one of various SIM card related error messages, such as SIM Failure, Invalid SIM, No SIM, No SIM Installed, etc., popping up on their iPhone 18 Pro or iPhone 18 Pro Max. You may also have seen a notification like Searching, No Service, or SOS on the iPhone 18 Pro screen.
Are you encountering SIM card related errors on your iPhone 18 Pro after an upgrade, causing the absence of cellular signal bars? If your SIM card does not work due to these errors, making calls, using mobile/cellular data, and sending or receiving SMS texts will not be possible. As a side note, you may still be able to send iMessages and make regular Wi-Fi calls. The good news is that you may be able to troubleshoot and resolve the issue quickly.
Please try following the steps below, in this order, until your issue is resolved.
1. Turn Airplane mode on and off
Begin by navigating to iPhone Settings or the Control Center and enabling Airplane mode. After a 15-second wait, disable Airplane mode. If your carrier name appears in the status bar or Control Center, it indicates that the SIM card is functioning properly.
2. Restart your iPhone 18 Pro
Restarting is always a good idea. Restart your device to see if you can fix this issue. If you are just starting to use a new SIM card, always restart first. Here is how:
- Press and hold either volume button and the side button until the power-off slider appears.
- Drag the slider, then wait 30 seconds for your device to turn off.
- To turn your device back on, press and hold the side button until you see the Apple logo.
3. Update your iPhone
Apple may have released a new iOS 27 version to address this problem. Go to Settings > General > Software Update to check for updates. If there is an update, tap Download and Install and follow the instructions on the screen.
4. Check for a carrier settings update
Especially after major iOS releases, carriers may release updates to ensure that their service is working perfectly with iOS. These types of updates do not occur often. To check this, go to Settings > General > About. If there is an update, a popup will appear. Tap Update to install it. If your carrier has released a mandatory update, you will see an OK button instead. Please ensure that your iPhone 18 Pro is connected to Wi-Fi, as this requires an active internet connection. If you do not have Wi-Fi, find a Wi-Fi network and try this step again.
5. Check to see if your SIM card is damaged
Remove the SIM card from your iPhone, wipe it gently with a soft, dry cloth and place it back in. Please note that this step is applicable for an iPhone 18 Pro with a physical SIM card. In some countries and regions, iPhone 18 Pro and iPhone 18 Pro Max are sold as eSIM-only and do not have a SIM tray: the United States, the United States Virgin Islands, Canada, Mexico, Japan, Guam, the United Arab Emirates, Saudi Arabia, Bahrain, Kuwait, Qatar and Oman.
- Eject the tray with a paper clip or a SIM-eject tool. Insert it into the hole beside the tray and push in, towards your iPhone, but do not force it. If you are having difficulty ejecting the tray, Apple says to take your iPhone to your carrier or an Apple Store rather than forcing it.
- Now remove the SIM card and clean it with a dry, soft cloth. Be gentle.
- Then, put the card back into the tray. Please ensure that the notched corner matches the notched corner of the tray.
- And push the tray back in.
If you see visible damage to the SIM, contact your carrier and ask for a replacement, as we explain in the next step.
6. Contact your carrier
You can contact your carrier by phone or by visiting their local store. Tell them about your problem. And ask them for a SIM card replacement. Carriers will either replace the card at no cost or for a nominal fee.
7. Reset your network settings
If your issue continues, try this step. Please note that when you choose to Reset Network Settings on your iPhone 18 Pro, it means you are initiating a process that will revert all network-related settings to their default configurations. This action includes Wi-Fi passwords (you will need to reenter them afterward), VPN settings and more. Apple also notes that your iPhone’s name resets to “iPhone” and cellular data roaming may be turned off. But you should also know that your content (photos, files, etc.) and other data stay intact. To do this, go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings.
