Make sure Airplane Mode is turned off. To turn off Airplane Mode, tap Settings > Airplane Mode.

Check the top left corner of iPhone's display to make sure you have a strong signal . If not, try changing your location or going outside.

If you are trying to access the internet, make sure you have a valid data connection by checking next to the carrier name at the top of the screen for one of the following indicators:

• LTE*
• UMTS/EV-DO
• EDGE (GSM models only)
• GPRS/1xRTT
• Wi-Fi

To reset your network settings, tap Settings > General > Reset, then scroll down and tap Reset Network Settings.

If your iPhone has a SIM card:

Step 1: Remove the SIM card by inserting the end of the SIM eject tool, or a small paper clip, into the hole on the SIM tray.

Step 2: Press firmly and push it straight in until the tray pops out.

Step 3: Gently remove the SIM card from the tray, then reposition the SIM card back in the tray.

Step 4: Return tray to iPhone, then push to fully reinsert.

Updating your iPhone may solve your issue

To update wirelessly, tap settings > general > software update and follow the on screen instructions.

If you can't update wirelessly, try connecting to a computer and using iTunes to update your iPhone. For more information, see this article.

For questions about network status, coverage area, billing, and other related issues, get help from your carrier.