Why calls drop, and what you can do about it

Call drops usually happen because your phone loses a usable signal: you are at the edge of a cell, inside a building that blocks it, moving fast between masts, or the cell is overloaded. Sometimes the cause is the phone itself, its SIM or a network fault. Find out where and when calls drop, then match the fix to the cause.

What causes call drops?

Weak signal at the edge of a cell. Each mobile mast covers an area called a cell. Near its edge, signal is weak and quality is poor. The call may hang on for a while and then fail.

A failed hand-over. When you move, your phone passes the call from one cell to the next. If the next cell is weak, busy or on a different technology, the hand-over can fail and the call drops. This is common on trains, motorways and in lifts.

Buildings and basements. Walls, metal, concrete and coated windows absorb mobile signal. A call that starts outside may drop as you walk deeper inside. See why signal is weak inside buildings and basements.

Congestion. At busy times, like events or rush hour, a cell can run out of capacity. Calls may fail to connect or drop.

Interference and poor quality. Even with decent signal strength, a noisy signal can make calls break up. Signal quality is a separate measure from signal strength.

Phone or SIM issues. An old or damaged SIM card, out-of-date software, a faulty antenna or a case with metal parts can all play a part.

Network faults or maintenance. Sometimes a nearby mast is down or being worked on.

How to find the cause of your call drops

1. Note where it happens. Always in the same room, street or stretch of road? That points to coverage.
2. Note when it happens. Only at busy times? That points to congestion.
3. Check your signal there. Look at the strength in dBm and the network type. Readings in dBm are more useful than bars.
4. Note the band and cell. If calls drop when the phone moves to a particular cell, that cell may be weak or faulty.
5. Test another phone or SIM. If a different phone on the same network has the same problem, it is the network. If not, it is your phone or SIM.
6. Ask people nearby. If neighbours on the same network have the same issue, it is coverage.

Fixes that help

Move a few metres. Near a window or a different side of the building can make a big difference.

Turn on Wi-Fi calling. If your carrier supports it, calls go over your home Wi-Fi when the mobile signal is weak. Our guide to Wi-Fi calling explains when to use it.

Restart your phone. It is simple, but it makes the phone search for the best cell again.

Update your phone. Software updates often include fixes for the modem and network settings.

Check the preferred network type. On most phones, search Settings for "preferred network type" or "network mode". Make sure it is set to the most capable option, such as 5G or 4G, so the phone can use voice over 4G (VoLTE) where available.

Ask for a new SIM. SIM cards wear out, and older ones may not support newer features. Carriers usually replace them.

Report it with details. If the drops are in a fixed place, your carrier needs to know. Dates, times, places and signal readings help them take it seriously.

Does airplane mode help?

Turning airplane mode on and off forces the phone to reconnect, much like a restart. It can help when the phone is stuck on a poor cell after you move. It does not create signal. Our guide on the airplane mode trick explains what it really does.

When to talk to your carrier

Contact your carrier if:

• Calls drop in the same place for days or weeks.
• Other phones on the same network have the same issue there.
• You have tried a restart, an update and a new SIM.

Bring evidence. A list of dates, times and places, with signal readings, is far more useful than "my calls keep dropping". Our guide on why a signal history helps when you complain shows how to build one.

How CellRadar helps

CellRadar shows your live mobile signal in dBm with network type, carrier, band and cell ID, so you can see what changes when a call drops. The signal map puts your own readings on a map, and the history and reports feature saves them as PDF or CSV for your carrier. It cannot strengthen the signal, but it gives you clear evidence of where it is weak.

Frequently asked questions

Why do my calls drop in the same place every day?

That usually means weak coverage or a poor hand-over between cells at that spot. Note the place and your signal reading there, and report it to your carrier.

Can a case cause call drops?

A case with metal parts or a magnetic plate can weaken signal in some phones. Try a call without it in a weak spot to compare.

Why do calls drop when I switch from Wi-Fi to mobile?

With Wi-Fi calling, the phone hands the call from Wi-Fi to the mobile network as you leave. If mobile signal is weak at that moment, the call can drop.

Do 5G phones drop fewer calls?

Not necessarily. Calls depend on coverage and signal quality where you are, whatever the network type.