When you see "SOS Only" on your iPhone, it means that your device is not connected to a cellular network that is able to use typical cellular connectivity. This warning appears when your iPhone is outside your carriers coverage area, so you wont have normal calling, texting, or internet access. However, you can still make emergency calls to numbers like 911 (US), 112 (Europe), 999 (UK), or 000 (Australia) .

Here are some reasons why your iPhone may show an "SOS Only" message and how to fix it:

• Network coverage: Your iPhone may display this message when youre in an area with poor or no network coverage. Wait until you move to a location with better coverage.
• Carrier issues: You may see the "SOS Only" message if your carrier has issues with network coverage or the server is down. Contact your carrier to verify that your account is active and in good standing, and that there are no outages in your area.
• SIM card issues: Your iPhone may display the "SOS Only" message if your SIM card is not correctly inserted or has been damaged. Check that your SIM card is correctly inserted and not damaged.
• iOS updates: Sometimes, updating your iOS can cause network connectivity issues on your iPhone, leading to an "SOS Only" message. Update your iPhone to the latest version of iOS.
• Airplane mode: If you have turned on airplane mode but forget to switch it back off, your iPhone may not connect to the cellular network. Turn off airplane mode.

If none of these solutions work, you may need to contact your carrier for further assistance.