If your Fairphone 5 shows a "Not registered on network" error or you can't make calls, it's a frustrating roadblock. This error means your phone can't connect to your carrier's cellular network, so calls, texts, and mobile data won't work. The good news is, it's often a software or settings hiccup you can fix yourself.
Before diving in, check your IMEI number by opening your phone dialer and entering *#06#. You should see a 15-digit number. If it shows "null" or all zeros, that points to a deeper issue. Most of the time, though, a simpler fix will get you back online.
Restart Your Fairphone 5
It sounds too simple, but a restart clears temporary software glitches that can interfere with the modem. Press and hold the power button until the menu appears, then tap "Restart." Wait for the phone to fully boot up before checking your signal. If the standard restart doesn't work, try a force restart by holding the power button for over 10 seconds until the screen goes black and the phone reboots.
Toggle Airplane Mode
This quickly resets your cellular radio without a full reboot. Swipe down from the top of your screen to open the Quick Settings panel and tap the Airplane Mode icon. Wait about 15 seconds, then tap it again to turn it off. Your phone will then search for and attempt to register on the network from scratch, which often resolves the error.
Remove and Reinsert Your SIM Card
One of the advantages of the Fairphone's modular design is easy access. Power the phone off completely. Use the SIM eject tool to pop open the SIM tray on the side of the phone. Take out the SIM card, inspect the gold contacts for any dirt or damage, and gently blow on the tray slot to clear dust. Reinsert the SIM card firmly and power the phone back on. A poor connection here is a common culprit.
Check Your Carrier Account Status
Sometimes the problem isn't your phone at all. An unpaid bill, expired prepaid credit, or a carrier-side service outage will prevent registration. I'd recommend using another device to log into your carrier's website or app to check your account status. You can also call their customer service from a different phone to confirm everything is active on their end.
Reset Your Network Settings
This clears all your saved network configurations, including Wi-Fi passwords and Bluetooth pairings, and can fix corrupted cellular settings. Go to Settings > System > Reset options. Tap on Reset Wi-Fi, mobile & Bluetooth and confirm. Your phone will restart. Afterward, you'll need to reconnect to Wi-Fi networks and re-pair Bluetooth devices, but it often resolves persistent network registration problems.
Manually Select Your Network
Your phone might be trying to latch onto a weak or incompatible network tower automatically. You can force it to search for and connect to your specific carrier. Go to Settings > Network & internet > SIMs. Tap on your SIM card and then select Network operators. Turn off "Choose automatically." Your phone will search, then show a list. Select your carrier's name from the list and see if it successfully registers.
Update Your Phone's Software
Fairphone is committed to long-term updates, and these often include fixes for connectivity bugs. An outdated Android version could have a known issue that's already been patched. Go to Settings > System > System update and tap "Check for update." If an update is available, install it. The phone will restart, and it's worth checking your network connection immediately after the update completes.
Change the Preferred Network Type
If you're in an area with spotty 5G, forcing your phone to use LTE might result in a more stable connection. Navigate to Settings > Network & internet > SIMs and tap on your active SIM. Look for "Preferred network type" and try changing it from "5G" to "LTE" or even "3G/2G" temporarily. If you get a connection on a lower band, the issue might be related to 5G coverage or configuration in your area.
Try a Different SIM Card
This test determines if the problem is with your SIM card or the phone itself. Borrow a known-working SIM card from a friend (ideally on the same carrier) and insert it into your Fairphone 5. If the new SIM card connects without any "not registered" errors, then your original SIM is likely faulty or deactivated. You'll need to contact your carrier for a replacement. If the borrowed SIM also fails, the issue is with the phone.
Perform a Factory Reset
This is your last resort software fix. A factory reset wipes the phone back to its original state, eliminating any deep-seated software corruption. Make absolutely sure to back up all your important data, photos, and contacts first. Go to Settings > System > Reset options > Erase all data (factory reset). Follow the prompts to confirm. After the reset and setup, test with your SIM card immediately. If the error persists after a clean slate, the issue is likely hardware-related.