Unwanted PPI, injury claim or PC virus phone calls seem to be out of control, and with all of our personal details being logged, sold on and probably stolen by nefarious hackers, there seems to be no way out when it comes to spam calls. If you're getting repeated calls from an unwanted number, be it someone you know who you don't want to talk to, or an over-the-phone fraudster, all three of the major smartphone operating system providers have solutions. We'll take you through how to block phone calls on your iPhone, Android, Samsung Galaxy and Windows Phone.
Block calls through your mobile network
The solutions we outline below won't stop people from being able to leave you messages via your answerphone/voicemail. It also won't prevent people from contacting you via other means, such as WhatsApp. We'll go through that below.
If you are getting repeated calls from a phone number, Ofcom advises you contact your provider and report it to them. Different providers will handle this differently. You can see the policies of each of the major phone network providers via the links below. Using a phone's call blocking function just prevents you from being notified about the call and the call being added to your call history log. None of the UK's networks are able to block a specific number from calling your phone; they will simply let you change your phone number, sometimes for a fee.
Most importantly: if you are receiving calls you consider to be threatening, don't simply block the caller, report it to the police. If you're receiving calls from withheld numbers that are threatening, the police may be able to work with your mobile phone network to trace the call.
Three's advice on malicious calls: Call the police and then call Three on 333.
Vodafone's advice: Log your calls via a a PDF form. If you receive three or more calls it'll be reported to the Nuisance Call Bureau.
O2's advice: Text them information about nuisance calls and they'll pass it to the ICO.
EE's advice: text 7726 and then contact the ICO
GiffGaff's advice: Change your number
How to block calls and SMS on iPhone
It's easy to block phone calls on your iOS-powered iPhone. Tap on the Phone app (the green handset icon) and tap the Recents tab (see picture 1). Here you'll see a list of all your recent inbound and outbound calls. Each call has an 'i' in a circle next to it. Find the call that you didn't want to receive and tap the 'i' for that call. Now scroll down to the bottom of the page and tap 'Block this caller' (see picture 2).
You can also block people who haven't called you yet. Go to Settings and scroll down to Phone. Tap on the 'Blocked' button (see picture 3) and you'll see a list of all the numbers you've blocked. This will also prevent you from receiving FaceTime and SMS messages.
To unblock any number on this list, tap the 'Edit' button the top-right and then tap the red symbol next to the number you want to unblock and then tap Unblock. You can also unblock a number by finding it the Recents menu and tapping the 'i' icon as before and scrolling down to 'Unblock'.
How to use Do Not Disturb for iPhone to silence unwanted nuisance calls
Blocking calls from nuisance numbers isn't completely reliable as scammers tend to change numbers fairly often. A better method is to silence calls from numbers not in your contacts list, using Do Not Disturb. Go to Settings and select 'Do Not Disturb'. Toggle 'Manual' mode to on and ensure 'Allow Calls From' is enabled for your contacts. You'll still receive calls from everyone, but only calls from contacts will vibrate the phone and activate the ringer.
The Repeated Calls function is a handy one; scammers don't tend to call multiple times in quick succession so if someone who isn't in your contacts is trying to call you in an emergency you'll get a proper call notification if they call twice or more in succession.
How to block calls on an Android phone
Because there are so many Android phones with different designs, these steps can't be applied to every phone. There are, however, some general rules
How to block calls on Android Marshmallow
You can block calls on phones running stock Android Marshmallow by going to the Dialler app (phone icon) and tapping the three dots icon on the top-right (image 1). Select 'Settings' and then 'Call blocking'. Here you'll see a list of the numbers you've blocked (image 2) and you can add a specific number from here, too. To block a number that's called you recently, go to the Recent tab (clock icon) and tap and press on the caller whose number you want to block (image 3). When the menu pops up, select Block Number.
How to block calls on a Samsung Galaxy phone and other older Android phones
Depending on the age of your Samsung Galaxy or other Android phone, you will have a few options on how to block numbers.
On an older Samsung Galaxy phone, such as the Galaxy Ace 2 and similar cheap Android phones, go to the Dialler app (Phone icon) and tap on the Logs tab (image 1). Find the caller you want to block and tap and hold your finger on it until a menu pops up. Then select 'Add to rejected list'. To manage the rejected list find the Settings button on your home screen and scroll down to Call (image 2). Here you can manage your numbers and how your phone reacts to unknown callers (image 3) This might be hidden in a tab called 'My device' depending on your phone.
On newer Android devices you'll find call blocking features in the Phone app by tapping on the 'More' button on the top-right of the screen (image 1). Hit 'Settings' and then select 'Call rejection', then 'Auto reject list' (image 2). Here you can select recent calls from your Log (image 3), add a new phone number or select one from your contacts. You can also set up automatic rejection for all unknown numbers, which means anyone who isn't in your contacts will be automatically rejected. This differs from Do Not Disturb, which is available on recent versions of Android, because you won't even be informed the call has taken place, while Do Not Disturb just silences the ringer.
Other devices with alternative interface designs will differ slightly but, generally speaking, you'll find features called 'Call blocker', 'Harassment filter' or 'Auto reject' either in the Dialler app or in the Settings menu. 
How to block calls on a Windows Phone
Depending on the make and model of your phone, and which network you're with, you may have an app called 'call + SMS' filter or, if you're running Windows 10 an app called Block and Filter. From within these apps you can manage your blocked numbers.
How to block someone in WhatsApp
Blocking a contact in WhatsApp varies by which phone operating system you're running.
On Android, go to your list of chats, tap the three dots button on the top right of the screen, then Settings>Account>Privacy>Blocked Contacts. Tap the small button on the top right to add contacts to your block list.
On the iPhone, go to the relevant chat and, at the top of the screen, tap the contact's name. Then scroll down to Block this contact.
On Windows Phone, go to the relevant chat and tap the three dots button at the bottom of the screen. Then tap Block.
