Why Does My Phone Say No Service but I Have WiFi?

Phone shows no service but WiFi works fine? This guide explains why cellular and WiFi are separate, what causes no service or SOS mode, and how to fix it step by step.

You are connected to WiFi, your apps are loading, and everything on the internet side of your phone is working fine. But the cellular signal bars are gone and the status bar shows No Service or SOS. If you are wondering why your phone says no service but you have WiFi, the short answer is that WiFi and cellular are two completely separate connections. Having one does not guarantee having the other. This guide explains exactly what causes no service while WiFi still works and how to fix it on both iPhone and Android.

Why Does My Phone Say No Service but I Have WiFi

WiFi and Cellular Are Not the Same Thing

This is the most important thing to understand before anything else. Your phone connects to the internet in two different ways, and they run on completely separate infrastructure.

WiFi connects your phone to a local router in your home, office, or wherever you are. That router connects to the internet through an ISP (Internet Service Provider) via a cable or fiber connection. WiFi uses radio waves in the 2.4GHz or 5GHz range and has nothing to do with your phone carrier.

Cellular service connects your phone to towers operated by your carrier (AT&T, Verizon, T-Mobile, etc.). Cellular handles phone calls, SMS texts, and cellular data. It runs on entirely different frequencies and infrastructure than WiFi.

When your phone shows No Service, it means it cannot reach your carrier’s towers. Your WiFi connection keeps working because it does not use your carrier’s network at all. The two systems do not depend on each other.

Why Is My Phone Showing No Service?

You Are in a Low Coverage Area

The most straightforward reason is that you are somewhere your carrier does not reach well. Basements, rural areas, buildings with thick walls, and certain geographic areas all reduce or eliminate cellular signal. Your router is still right there in the building broadcasting WiFi, so that connection stays strong even when cellular drops out.

Carrier Outage in Your Area

Carriers experience outages. When a local cell tower goes down or there is a network issue in your region, everyone connected to those towers loses service. Your WiFi continues because it connects through a completely different system. You can check your carrier’s website or app for outage updates in your area.

SIM Card Issue

A loose, damaged, or improperly seated SIM card prevents your phone from authenticating with your carrier’s network. The result is No Service even in areas where your carrier normally has strong coverage.

Try removing and reinserting your SIM card:

Use the SIM ejector tool to open the SIM tray on the side of your phone.
Remove the SIM carefully.
Check for any visible damage or debris.
Reinsert firmly and restart your phone.

If the SIM is damaged, your carrier can replace it for free or low cost.

iPhone Stuck in SOS Mode

If your iPhone shows SOS or SOS Only instead of your carrier name, your phone is connected to an emergency-only network. An iPhone stuck in SOS mode cannot make regular calls or use cellular data. It can only call emergency services.

This happens for the same reasons as No Service: poor coverage, carrier outage, or a SIM or software issue. The SOS label is Apple’s way of showing that your phone has a limited emergency connection rather than nothing at all.

To try to get out of SOS mode on iPhone:

Toggle Airplane Mode on, wait 15 seconds, then toggle it off. This forces the phone to search for and reconnect to available networks.
Restart your iPhone by holding the Side button and a Volume button until the slider appears.
Check that your carrier settings are up to date: Settings > General > About and wait for a carrier update prompt.

Account or Plan Issue

If your plan has expired, there is a billing problem, or your account has been suspended, your carrier restricts your service. The phone shows No Service because it cannot authenticate to the network with a restricted account. WiFi still works because it has nothing to do with your carrier account.

Check your carrier’s app or website (you can do this over WiFi) to see if there is an account issue. Log in and look for any alerts, payment failures, or plan status notifications.

Why Is My Cellular Data Not Working Separately from Calls?

Sometimes the No Service issue only affects cellular data rather than calls and texts. In this case, calls still go through but mobile data does not load anything when you are off WiFi.

This usually comes down to one of three things:

Mobile data is turned off. Check Settings > Cellular on iPhone or Settings > Network and Internet > Mobile network on Android and make sure mobile data is enabled.
Data roaming is off and you are in a different region. If you have traveled and data roaming is disabled, your phone cannot access cellular data outside your home network. Enable roaming in the same settings menu if you need it.
APN settings are incorrect. APN (Access Point Name) settings tell your phone how to connect to your carrier’s data network. Incorrect APN settings prevent cellular data from working even when calls go through fine. These are usually set automatically, but after a carrier switch or SIM change, you may need to enter them manually. Contact your carrier for the correct APN settings if you suspect this is the issue.

Step-by-Step Fixes for No Service with WiFi Working

Work through these in order.

Toggle Airplane Mode. Turn it on, wait 20 seconds, turn it off. This forces a fresh search for cellular towers.
Restart your phone. A restart clears temporary network errors. On iPhone, hold the Side and Volume buttons until the slider appears. On Android, hold the power button and tap Restart.
Check for carrier settings update (iPhone). Go to Settings > General > About and wait 10 seconds. If a carrier update is available, install it.
Remove and reinsert the SIM card. Physical connection issues with the SIM cause No Service. Reseat it and restart.
Check your account status. Log into your carrier account over WiFi and look for billing or plan issues.
Reset network settings. This clears cellular configuration and starts fresh.
- iPhone: Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings
- Android: Settings > General Management > Reset > Reset network settings
Update iOS or Android. An outdated OS version can cause cellular connectivity issues. Update through Settings and restart after.
Contact your carrier. If nothing above resolves it, your carrier can check your account, confirm whether there is an outage in your area, and diagnose SIM or network registration issues from their end.

Using WiFi While Cellular Is Down

Until the cellular issue is resolved, your WiFi connection keeps most things working. You can:

Browse the internet and use apps normally
Make calls through Wi-Fi calling if your carrier supports it (Settings > Phone > Wi-Fi Calling on iPhone)
Send iMessages over WiFi to other iPhone users
Use messaging apps like WhatsApp, FaceTime, and Signal over WiFi

Standard phone calls and SMS texts that require cellular will not work until service is restored.

The Short Answer

Your phone shows No Service while WiFi works because they are separate systems. WiFi connects through your router, cellular connects through your carrier’s towers. No service means the carrier connection is down, which happens due to poor coverage, a carrier outage, a SIM issue, or an account problem. WiFi keeps working because none of those things affect your router. Start with Airplane Mode toggle, restart your phone, check your SIM, and verify your account status. If your iPhone is stuck in SOS mode, the same steps apply. Enable Wi-Fi calling to make calls in the meantime.