Nuisance calls are the bane of the modern age. If you're not being rung up by a teenager in a call centre about switching energy supplier, it's someone about PPI, or maybe a grumpy ex-boyfriend. They're enough to turn the advantages of a mobile phone - easy communications, wherever and whenever - into a curse. Fortunately you can block specific callers, enabling you to avoid them safely without having to cut yourself off from the people you want to talk to.

In this tutorial we show how to block an unwanted caller's phone number on an iPhone in iOS 7 (which is easy) and in iOS 6 (which is more difficult). We also explain how to find out if someone has blocked your number.

If you'd rather watch the process than read about it, however, take a look at our video tutorial:

Until recently the iPhone didn't offer a straightfoward way to block an incoming number: it could be done, but it involved sneaky workarounds or jailbreaking. But that all changed with the introduction of iOS 7, Apple's newest operating system for iPhone (and iPad and iPod touch too).

(For more information about iOS 7, we also recommend this list of iOS 7 tips and our roundup of new features in iOS 7.1.)

How to block calls on an iPhone

Stop ringing me up! (Cropped) photo by oddharmonic, used with permission under terms of Creative Commons Licence

Here's how to block an unwanted caller's numbers on an iPhone, whether it's an iPhone 5s, iPhone 5ciPhone 5, iPhone 4S or an earlier model - even the iPhone 3GS, which can't run iOS 7. And we explain how to block numbers in iOS 7 (which is easy) and in iOS 6 and earlier OS software (which is a bit more difficult).

How to block a number in iOS 7

How to block a number on an iPhone in iOS 7

Let's start with the easier task. Blocking a nuisance caller's phone number in iOS 7 is simple.

Say you receive a call and want to block that person's number. Simply go to your list of recent callers (from the Home screen you can open the Phone app, then clock on the Recents tab at the bottom). Click the 'i' symbol next to the unwanted number, then scroll down to the bottom of the resulting screen and clock Block this Caller, then confirm your decision. You won't be bothered with any calls, texts or FaceTime link-ups from that number.

(When we tried calling an iPhone that had blocked us, we heard a single ring, and were then diverted to the O2 messaging service, where we recorded a message. But the iPhone didn't ring, or show the number in its recent calls, and we couldn't find any new voicemail.)

How to block a number in iOS 7

We didn't appreciate being contacted by that blurred-out number at the top, so let's block it. Click the 'i' to the right of the number and we'll see this screen (scroll down to the bottom):

Block a phone number in iOS 7

Alternatively, go to the Settings app and scroll down to the Phone section. Scroll down again and click Blocked, and you'll see your list of blocked callers. Hit Add New and pick further numbers to block from your contacts list. (You'd need to add the nuisance caller to your contacts list for this method to work, however.)

How to block a number in iOS 7

How to unblock a number on an iPhone in iOS 7

The second method comes into its own when we reverse the decision. Go to Settings, Phone, Blocked and hit Edit. Click the red circle next to the blocked number you want to unblock, and a red button will appear. Press that.

How to block a number in iOS 7

Alternatively - and more helpfully if you change your mind right away - you can simply tap the 'Block this caller' option again, after clicking the 'i' symbol next to a recent number (it changes to 'Unblock this caller' when you block them).

Have I been blocked in iOS 7?

What about when the boot is on the other foot? How can you tell if someone has blocked your phone number on their iPhone?

The sad truth is that you can't tell for sure without stealing their phone and checking the blocked list. (Or you could always, you know, ask them.) But there are definitely clues, to do with the length of time your phone rings before being diverted to voicemail: a blocked call will always ring exactly once, as far as our experiments show.

We look in more depth at some of the clues that let you know if you've been blocked in iOS 7 in a separate article: How to tell if someone has blocked your phone number on iOS 7.

Can I block a number on an iPhone in iOS 6?

The advice we'd offer first of all is to update to iOS 7 - it's free and brings numerous useful features. Not everyone likes the colourful new look (although we reckon you'll get used to that). However, some devices simply can't run iOS 7 - any iPhones before the iPhone 4 are incompatible, and the iPhone 4 doesn't get access to all the features.

So ok - let's say you're sticking with iOS 6. You can still block a number on an iPhone in iOS 6, but it's a lot trickier. If you don't want to put up with problem callers and aren't willing to update to iOS 7, there are two techniques you can use to block nuisance callers on your iPhone. (A third technique would be to change your number, sadly.)

1. Jailbreak your iPhone, and block numbers using Call Blocker, Call Bliss or another unofficial app

'Jailbreaking' your iPhone means bypassing the locks put in place by Apple to prevent unauthorised apps being used on the phone. Once your break these restrictions, you gain access to a large number of unofficial apps, many of which offer features you'd never otherwise be able to access; but jailbreaking is legally ambiguous, risky, and certain to void any warranties you have with Apple. Therefore our advice is to think long and hard before going ahead with the jailbreaking process. (What's more, the known methods for jailbreaking the iPhone 4S and later won't work if you've updated to iOS 6.1.3 or later, so you'll have to jump ahead to solution 2.)

If you decide to jailbreak your iPhone (and have heard and understood our warnings), we have full iPhone jailbreaking instructions here. As we said, you'll need to be using iOS 6.1.2 or earlier to achieve a long-term jailbreak - the most recent updates fixed the flaw that allowed the process to work. (iOS 7 hasn't been jailbroken yet, incidentally, but we expect it will be soon.)

iBlacklist Cydia app

Once you've jailbroken your iPhone, you need to find a call-blocking app. Search on the Apple App Store and the independent Cydia app store. The blocking app we are going to use is called iBlacklist, which is on Cydia. It costs $12.99 (about £8.50) and offers the ability to block calls and SMS messages from specific numbers, as well as all unknown numbers.

Install iBlacklist, restart your iPhone, open iBlacklist and click 'Blacklists'. To add a phone number to your blacklist, hit 'Add new Blacklist' and add it manually (you can do this via your recent call list). Once you've added a number, set the 'Call' icon to 'On'. To block text messages do the same thing with the 'Message' icon.

Now you need to configure what happens when a call comes in from a blacklisted number. Hit 'Action to be performed'. Options include blocking before your phone even acknowledges the call, sending back the engaged tone, sending the caller directly to voicemail, or automatically hanging up the call. Finally, hit the blue button to save your selections and that number is blocked.

2. Set up an 'unwanted caller' contact

That was the nuclear option, and certainly the most effective. However, we don't much like the idea of jailbreaking our iPhones, so we prefer this canny workaround.

Create a contact from the number you were called on. Instead of naming it after the person or company, however, call the contact 'Nuisance Caller', 'Hang Up' or some other label that you'll understand. When it comes up you'll know that it's an unwanted caller, and won't pick up.

How to block a number on an iPhone 5

Unwanted caller iPhone Contact

It may look like I'm calling my 10-week-old son an idiot, but I'm not! Poor little chap.

And it doesn't just work on one number. Every time a different timewaster calls you, simply bring up the recent calls screen, tap the arrow by the number and hit 'Add to Existing Contact'. Then add them to the previously created contact.

But wait: it gets better. To save you the trouble of looking at your phone to see who's calling, you can set a specific ringtone to the troublemaker contact. The robot, say, or the quacking duck. Better still, you can set it to a silent ringtone. You'll need to create the ringtone yourself, but it's very easy. Just create a silent sample in GarageBand, then save it as a ringtone.

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See also:

How to jailbreak your iPhone

How to update your iPhone or iPad to Apple iOS 7

How to stop iPhone neck and iPad shoulder

How to fix a water-damaged Apple iPhone

How to protect your iPhone from thieves