The iPhone 6 and 6 plus are the most popular phones in the world. However when I get my iPhone brand new 6, it always bother me with no service problem. If you also see No Service or Searching on your device, or can’t connect to a cellular network or cellular data, follow these steps:
Toggle Airplane mode
In some case, like changing network base station, your iPhone could lose connection. Then you can try to toggle airplane mode. This is the most simple and crazy solution to solve many networking problems.
Just go to Settings, turn the Airplane on, wait for about 5 seconds and then turn it off again.
Check the carrier setting updates
This may do the trick and fix the problem. The first thing you need to do is connect to the Wi-Fi network. Click on Settings, then on General, and then About.
Reset network settings
If your iPhone still don’t have a cellular network, you can try to reset network settings. Go to Settings, choose General, Reset and then click the Reset network Settings.
Attention: Reset network settings will clear your saved Wifi connection password, cellular settings, and VPN and APN settings.
Update your iPhone to latest iOS
Apple always make improvement to their service. Some bugs in old iOS could cause the no service issue. Try to update your iPhone 6/6 plus to the latest iOS may solve the problem. Ridiculously，sometimes, degrade to an old version iOS may get problem solved.
Restart your iPhone
Restarting is always the useful solution to many iPhone issues. If the problem is caused by software, restart your iPhone always works. Even the randomly shut off issue on iPhone 6s can be solved by this simple solution too.
Usually, these ways to fix no service on iPhone are more than enough, and the service is back on. If not, contact Apple or visit their stores to see what other things you may try.