A No SIM message means your phone can't see your Flex Mobile service. It's usually a seating or software issue, and it's usually fixable in a few minutes.
If you use a physical SIM card
- Restart your phone. This alone clears the message more often than anything else on this list.
- Turn the phone off, eject the SIM tray, and check the SIM is flat in the tray with the gold contacts facing down and the notched corner lined up.
- Wipe the gold contacts gently with a dry cloth if they look dusty, then put the tray back in until it sits flush.
- Turn the phone on and wait up to two minutes. Flex Mobile appears in your status bar with signal bars.
- If it still says No SIM, put the SIM in a different unlocked phone. If it works there, the tray or reader in your original phone is the problem. If it doesn't work in either, contact Flex Mobile support for a replacement SIM.
If you use an eSIM
- Open Settings and find your list of mobile plans. On iPhone this is Settings, then Cellular.
- Check that Flex Mobile is listed and turned on. If the switch is off, turn it on.
- If Flex Mobile isn't listed at all, the eSIM didn't finish installing. Go back to the activation guide and install it again.
- Restart your phone. Flex Mobile appears in your status bar with signal bars.
If it still says No SIM
Update your phone's software, then reset your network settings. Both are covered in their own articles. If the message persists after that, contact Flex Mobile support with your phone model and what you've already tried.