IMPORTANT: This article applies only to specific products and/or operating systems. Check Applicable Products and Categories for details.
In this article, we'll look at some of the potential reasons you're unable to call someone or receive their call. The two main reasons are a network or mobile provider issue on the one hand or a setting issue on the other.
We'll go from simple to more complex and rare scenarios.
The do-not-disturb mode is blocking all your calls.
Your phone has several options to manage incoming calls:
You can find the do-not-disturb mode by swiping down from the top edge of the screen and accessing the quick settings menu.
If it is enabled, you will not see any response to incoming notifications and calls. You only see missed calls and text messages when you use your phone. You can tweak the do-not-disturb mode by a long press on the corresponding quick-menu button and entering the do-not-disturb settings menu.
There's something wrong with the network signal.
The tiny vertical bars at the top right-hand side of your screen indicate your signal strength.
- If only the smallest bar is filled, or they're greyed out, or
- if the signal bars are marked with a little x or an exclamation mark (!)
it means your phone isn't connecting to the cellphone or Wi-Fi network (in case you're using an alternative telephone app to make calls).
People who call you will automatically transfer to voicemail, and you will not be able to make an outgoing call.
What causes poor signal strength?
- Distance from a broadcasting tower: in remote areas, signal strength can drastically reduce
- Physical boundaries: thick concrete reinforced walls can block the signal (e.g., underground parking garage).
Crossing country or territory borders
If you live near a country border, your phone switches country network. When that happens, you might experience your phone or mobile data signal might not activate immediately. Restarting your phone solves this issue.
Always verify if you haven't depleted your credit if you're using a prepaid subscription. In this case, you should still be able to receive calls, but you will be unable to make calls.
On rare occasions, your network provider might experience an outage. You can contact your mobile network provider or check this outage monitoring website. Usually, outages only take a while, so the issue should resolve itself.
It's possible to block specific telephone numbers or all calls from unknown or private numbers. You can check if these settings are causing your issue by going into your telephone app settings:
- Open your Phone app
- Tap More (upper right-hand side of the screen).
- Tap Settings ► Blocked numbers.
Sim card damage
A defective, old, or dirty SIM card might cause issues. Remove the SIM, clean off any dust or stains and reinsert it. Alternatively, insert your SIM card into another phone. If you can't make a call from another phone, your SIM card may be defective. Ask your network operator for a replacement SIM card.