If your Google Pixel 9 Pro shows "null or unknown IMEI" or displays "not registered on network" errors, you won't be able to make calls, send texts, or use mobile data. The IMEI is a unique 15-digit number that identifies your phone on your carrier's network. When it becomes corrupted, your device is essentially invisible to cell towers.
You can check your IMEI by opening your phone dialer and entering *#06#. If you see "IMEI Null" or a string of zeros instead of a proper number, your device needs attention. Before trying advanced repairs, work through these fixes in order. Many of them can resolve the network error without needing to directly address the IMEI.
Restart Your Google Pixel 9 Pro
A simple restart is always the best first step. When your phone powers back on, it performs a fresh network registration with nearby towers. This can clear temporary software glitches causing the error. Hold the Power button, tap Restart, and wait for a full reboot before checking your connection.
Toggle Airplane Mode
Switching Airplane Mode on and off forces your cellular radio to reconnect from scratch. Swipe down twice to open your Quick Settings, tap the Airplane Mode icon, wait 10 seconds, then tap it again to turn it off. This triggers a new handshake with your carrier without a full reboot.
Reinsert Your SIM Card
A SIM card that isn't seated properly can lead to network registration failures. Power off your phone, use the SIM eject tool to remove the tray, and carefully take out the SIM. Gently clean any dust from the card and the slot, then reinsert it firmly. Power your phone back on and see if it connects.
Verify Your Carrier Account Status
Sometimes the issue isn't with your phone. An expired prepaid plan, an unpaid bill, or a suspended account will show the same error. Log into your carrier's app or website, or call customer service from another phone. Make sure your account is active and in good standing before proceeding.
Reset Network Settings
This wipes all saved Wi-Fi networks, Bluetooth pairings, and cellular configurations. It clears corrupted settings that could be blocking network registration. On your Pixel, go to Settings > System > Reset options > Reset Wi-Fi, mobile & Bluetooth. Tap to reset, then let your phone restart and attempt a clean connection.
Manually Select Network Type
Your phone might be struggling with a specific network band. Switching from 5G to LTE can sometimes fix registration. Go to Settings > Network & internet > SIMs > Preferred network type. Try selecting "LTE" instead of "5G". If your phone connects on LTE, the issue may be related to 5G coverage or compatibility.
Update Your Phone's Software
Google and carriers release updates that fix network-related bugs. An outdated system may have known issues that are already patched. Go to Settings > System > System update and check for updates. Install any available updates, restart, and test your connection again.
Clear the Phone App Cache
The Phone app manages telephony functions, including network registration. A corrupted cache here can cause connectivity problems. Go to Settings > Apps > See all apps > Phone > Storage & cache. Tap "Clear cache". This doesn't delete contacts or call history, just temporary files. Restart your phone afterward.
Test a Different SIM Card
If other steps fail, your SIM card might be damaged. Try a working SIM from another phone in your Google Pixel 9 Pro. If the new SIM connects normally, your original SIM is faulty and you need a replacement from your carrier. If the new SIM also fails, the issue is with your phone's hardware or software.
Perform a Factory Reset
This erases everything and returns your phone to its original state. It's a last resort, so back up your data first. Go to Settings > System > Reset options > Erase all data (factory reset). After the reset, set up your device from scratch. If the network error remains after a factory reset, there is likely a hardware issue with the radio, and you should contact Google Support or a repair professional.