iOS 18.7.4 Network Connectivity Error After Update

What is the iOS 18.7.4 Network Connectivity Error?

Following the iOS 18.7.4 update released in late January 2026, some iPhone users experienced critical network connectivity failures. The issue prevented phones from connecting to cellular networks, making calls, or—critically—reaching emergency services. This prompted Apple to temporarily pull several iOS updates including iOS 18.7.4, iOS 16.7.13, iOS 15.8.6, and iOS 12.5.8.

The bug was first reported by Australian carrier Telstra and primarily affected older iPhone models. Apple has since pushed a carrier settings update to resolve the issue for most users.

When does it occur?

• Immediately after updating to iOS 18.7.4 or other affected versions
• When attempting to make or receive phone calls
• When trying to connect to mobile data networks
• Specifically affecting Telstra network users in Australia (initially)
• On iPhone 8, iPhone 8 Plus, and iPhone X models primarily
• After restarting the device post-update

Common causes

• Corrupted carrier settings bundle included in the iOS update
• Incompatibility between new iOS network stack and certain carrier configurations
• Failed carrier profile authentication during update installation
• Cellular modem firmware mismatch after iOS upgrade
• SIM card provisioning conflicts with updated network protocols
• Regional carrier bundle issues (particularly Telstra Australia)
• Interrupted update process corrupting network configuration files

Step-by-step fixes

1. Install the carrier settings update - Apple has released a fix. Go to Settings > General > About. Wait 30 seconds—if a carrier update is available, you'll see a prompt. Tap Update to install the carrier settings fix.

1. Toggle Airplane Mode - Open Control Center and enable Airplane Mode for 30 seconds, then disable it. This forces the iPhone to re-establish a connection with the carrier network.

1. Manually select your carrier - Go to Settings > Cellular > Network Selection > turn off Automatic. Wait for available networks to appear, then manually select your carrier. Re-enable Automatic afterward.

1. Reset network settings - Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This clears all network configurations and forces fresh carrier detection. You'll need to re-enter Wi-Fi passwords.

1. Remove and reinsert SIM card - Power off your iPhone. Use the SIM eject tool to remove your SIM card. Wait 60 seconds, reinsert the SIM, and power on. This forces re-authentication with your carrier.

1. Check for iOS update - Apple may have re-released a fixed version. Go to Settings > General > Software Update and install any available updates that address network issues.

1. Contact your carrier - Some carriers are pushing network-side fixes. Contact your carrier's support to verify your account is properly provisioned and request a network refresh to be pushed to your device.

1. Restore iPhone via iTunes/Finder - As a last resort, connect your iPhone to a computer. Open iTunes (Windows) or Finder (Mac), select your device, and click Restore iPhone. This reinstalls iOS completely with the latest corrected version.

If it still doesn't work

If you still cannot connect to your cellular network after trying all fixes, the issue may require carrier intervention. Contact your carrier to request a new SIM card, as the update may have corrupted SIM authentication data. For eSIM users, delete your cellular plan and re-add it through Settings > Cellular > Add Cellular Plan.

Apple has acknowledged this issue and is working with carriers to ensure all affected users receive the fix. If emergency calling is critical, keep your phone connected to Wi-Fi and use Wi-Fi Calling if your carrier supports it (Settings > Phone > Wi-Fi Calling). Monitor Apple's support pages for official guidance on iOS 16.7.13, which remains paused as of this writing.