Call blocking was one of the most convenient new iPhone features added as part of the iOS 7 update back in 2013 and the feature continues to be available in the most recent iOS - along with additional features that could stop nuisance calls from getting through.

We like the feature because it's a great way to avoid getting calls from people you don't want to speak to. But sometimes the person who needs to contact you might have a good reason to get in touch. Imagine a scenario where you are trying to call an estranged sibling to pass on sad news about another relative. If you were the one desperately trying to contact someone you may well wonder if you have been blocked and, if that is the case, is there anything you can do about it?

In this article, we explain the telltale signs: the way your phone behaves as you (unsuccessfully) try to get through, what response you'll get as you call, text and attempt to leave a message, the number of rings before you're diverted to voicemail and so on. We'll help you work out if someone has (for whatever reason) blocked you.

In iOS 13 Apple added a new feature that could mean your calls get ignored, although at least in this case you can leave a message. If your iPhone is running iOS 13 you can choose to Silence Unknown Callers, which is a handy feature if you are fed up with being plagued by calls from persistent telephone salesmen and other pests. This means that any calls from any number not in your contacts and recently made calls will go straight to voicemail.

It may well be the case that you haven't been blocked and that your number simply isn't in your friends contacts. Below we will discuss ways to get around this issue.

We explain how to block a number in our guide on how to block a number on any iPhone.

What happens when you ring a phone that has blocked you? Wondering what happened when you block a number or if you call a number that has blocked you? Read on... We tested out the blocking feature to find out the number of times a call will ring before being declined or sent to voicemail, the response when sending a text and so on, all of which will help us work out when we've been the victims of this feature in the future. We rang an iPhone that had blocked us, using a landline and multiple other iPhones. Unfortunately the results varied: sometimes we (the blocked caller) did not hear any rings at all, and were diverted straight to voicemail. At other times it rang once. So the giveaway number of rings is... "none or one". This is obviously annoying, and we haven't been able to work out what is causing the variation - it doesn't seem to be based on the carrier, as two EE phones behaved in different ways. But we can probably say that if your phone rings twice or more, you've not been blocked. As part of our testing we repeatedly left voicemails, but the recipient of the call did not receive a notification of either the missed call or the voicemail. As an aside, even though the recipient gets no notification that a message has been received, they may still receive it. If you've got visual voicemail, you just have to scroll down and find the 'blocked messages' folder, which appears under the 'deleted messages' folder only if you've had such a message. If you have to call your voicemail inbox, follow the usual procedure and it will report 'one new voicemail' and play the blocked message as usual.

What happens when you text a phone that has blocked you? We tried to send a text message to the phone that had blocked us. Everything proceeded roughly as usual: the text sent, and we got no error message. It was sent as an iMessage, and the text remained blue - our blocked iPhone didn't attempt to send it as an SMS. However, there was a bit of a giveaway. We didn't get a Delivered notification; in fact the person we were texting had read receipts switched on and we didn't get one of those either. And unsurprisingly the 'receiver' didn't get any message, or any notification.

Other reasons why they might not receive your call Here's where Apple's new Silence Unknown Callers feature in iOS 13 comes in. Since the introduction of iOS 13 it's been possible to set your phone so that it only receives calls from numbers in your Contacts or someone you have recently called. You can set this up in Settings > Phone. Then Scroll to Silence Unknown Callers and make sure it's switched on. This is a great way to ensure you never receive another call from a window-sales person again. However, sometimes you might be the one who needs to get in touch with someone who doesn't have your number. Perhaps you have a new number or perhaps you are borrowing a friend's phone. At least in this case you can leave a message for them, but in an emergency that may not be enough. There is potentially a way around this: the number needs to be in their contacts, or it could be one of the Siri Suggestions. The best way to get a number into Siri Suggestions is to email them with your contact details. We can't guarantee this will work if they don't even open the email, but it might! There are a few other reasons why your call might not get through, most obviously they may have turned their phone off, or they might have it on Do Not Disturb. To rule out the phone being switched off you could ring from a different number, or disguise your number using the relevant code for your country (141 from a UK landline, for instance), or by switching off call ID in the settings if you're using an iPhone (Settings > Phone > Show My Caller ID, then switch it off). Of course if they have the iOS 13 Silence Unknown Callers feature you would need to call them from someone whose Contact information will definitely be in their iPhone. If the phone really is switched off or set to divert, it will once again ring once and then go to voicemail. If they have Silence Unknown Callers on and the number you are calling from isn't in their contacts you will also go to voicemail. But if you were blocked, and the number you call from is in their contacts, either the person will pick up, or it will ring a few times until you ring off. Note that this may well be regarded as a sneaky or even harassing thing to do. It might just be better to get the message passed on by the person whose phone you were planning to borrow.

Do Not Disturb The other possibility is that your friend may not have blocked you; they may have just activated Do Not Disturb mode and thus, on a temporary basis, effectively blocked everyone. If they are using Do Not Disturb mode, the potential solutions and workarounds are slightly different to the ones you use to get round a user-specific block. To find out more, read how to tell if someone is using Do Not Disturb mode.