Missing calls on your iPhone? Or finding that your iPhone calls go directly to voicemail, and you don't know why? You're not alone.

In this article we discuss some simple issues that may be causing the problem, and explain how to fix them. Read next: How to manage voicemail on iPhone

iOS updates

When Apple updates iOS it's inevitable that some things will go wrong. Most of these should be picked up in the beta testing phase but a few will slip through.

When iOS 7 came out, some iPhones suddenly found that incoming calls were being directly transferred to voicemail. The option has since been disabled by default.

If you've noticed the voicemail problem since updating iOS, it's likely to be related; check for any new updates since then, which are likely to include a patch for this problem. Read more: How to update iOS on an iPhone.

Do Not Disturb mode

If the problem still persists, it's likely that the problem is caused by Do Not Disturb mode, which you may have activated by accident, or activated and then forgotten about - or may even have been switched on against your wishes by a glitch in iOS.

You can tell quite easily if you've got Do Not Disturb switched on, because there will be a crescent moon icon in the top right of the iPhone's status bar, next to the Bluetooth and battery icons.

How to stop iPhone calls going to voicemail: Do Not Disturb mode

When Do Not Disturb is enabled, calls and alerts that arrive will be silenced: that's the reason your calls are being diverted before you have a chance to answer them.

Turn off Do Not Disturb

The quickest way to turn off Do Not Disturb is via the Control Centre. Swipe up from the bottom of the screen to bring this up.

How to stop iPhone calls going to voicemail: Control Centre

The Do Not Disturb icon is in the top row: it's the crescent moon. Tap this and it will turn from purple (switched on) to grey (switched off).

Alternatively (although more slowly), you can turn it off via the Settings app.

Open the Settings app (it's the one with the grey cog icon).

In the second batch of options underneath Notification and Control Centre, you'll see a purple icon with that crescent moon and the words Do Not Disturb.

How to stop your iPhone going to voicemail: Settings

Click on that. Move the slider on Manual so that it's off - so there's no green on the slider.

How to stop your iPhone going to voicemail: Settings

Bingo! The moon should disappear from your iPhone status bar and you should start receiving your calls as they ring and not suddenly discover a bunch sitting unanswered in voicemail.

I don't remember setting my iPhone to Do Not Disturb; nor, it appears, do most people affected by this annoyance. Like I said, maybe it's a glitch, or maybe we've all just forgotten. Either way, this fix should sort the problem.

How do I stop my iPhone going to voicemail after just three rings?

This is a slightly different problem. Your voicemail isn't controlled by the iPhone itself, but by your network provider, and you have to adjust these settings by dialling your network and using a phone option.

First of all, check there isn't something weird going on with your network settings. Go to Settings > General > Reset Network Settings, then enter your passcode. This will ensure that you have the right settings for your network.

Whether you can change the length of time that the phone rings before going to voicemail depends on the network provider. Some, like Vodafone, enable you to change this using their automated system. Others require you to call up, or the amount is fixed.

Vodafone

Vodafone enables you to choose the length of time a phone rings before going to voicemail. According to the Vodafone instructions:

  • Enter **61*121*11*[Number of seconds]#

Then enter the number of seconds you'd like your phone to ring for (it has to be between 5 and 30 and a multiple of 5), followed by #.

For example, if you want to set if for 25 seconds, you'd enter **61*121*11*25#, then press call.

Vodafone will send you a text letting you know if this has worked.

Three

To adjust voicemail settings (including turning voicemail on or off) you need to call three on 333.

To turn off VoiceMail on the Three network, dial "333" and tap the "Keypad" in the Phone app. Press the the following buttons

  • 2
  • 1
  • 2
  • 3
  • 1
  • 1

You should get a text from Three stating that you have successfully turned off voicemail. To turn it on again go through the steps but change the last entry to "2".

O2

O2 has a direct line to turning voicemail on and off. Just dial the following numbers direct from your phone.

  • Turn voicemail off: 1210 
  • Turn voicemail on: 1750