Difference between 'No Caller ID' and 'unknown caller' as iPhone users left mindblown

Ever wondered why sometimes phone calls will come through as 'No Caller ID' and other times 'unknown caller'?

Turns out there's an actual reason for it, and it's not just phone manufacturers being inconsistent.

Unlike the early days of telephones, where you'd find out who was calling you after picking up, modern mobiles and smartphones allow you the option to pre-screen a call by telling you whether you're being contacted by someone you know or a random number everytime your phone buzzes.

Of course this doesn't apply to the times when the person on the other end has deliberately withheld their number; but let's be honest, no one answers those unless we're waiting for a call-back from the GP.

However, if you're prone to receiving calls from unknown numbers, then you may have noticed sometimes your phone will say 'No Caller ID' and other times 'unknown caller'.

Let's be honest, none of us answer these calls anyway (Getty Stock Images)

If you've ever thought this, you're not alone as the question has been asked numerous times on forums such as Reddit and Apple community support.

"Somebody called me with the caller ID of 'unknown caller'. What does that mean," asked a confused Redditor in one thread, adding: "I’m a bit spooked."

So why is this?

Difference between 'No Caller ID' and 'unknown number' explained

When it comes to numbers which ring through as 'No Caller ID', this is because the person calling you has made the decision to withhold their number. This can be done by one of two ways: dialling 141 before entering in a person's phone number or changing your settings to restrict your number on all outbound calls.

This is typically done by scammers or spam callers; Norton notes that 28 percent of anonymous calls are spam or fraud, but it is also used by doctors and law enforcement agencies when doing call-backs.

Turns out that mobile networks aren't being inconsistent after all (Getty Stock Images)

Which means it can be pretty tough to figure out whether to pick up the phone or ignore it.

You can also choose to silence calls from people who withhold their caller ID, however this may become an issue if it's a legitimate caller.

Meanwhile calls which come through as 'unknown caller' are likely due to issues with the mobile network.

Norton adds that 'unknown callers' can happen for several reasons, including:

• Issues with the network which prevent the caller ID from reaching your device
• Issues with your carrier's call filtering system
• International calling

This means the caller on the other end of the phone could very well be anyone, from your mother to someone stealing your bank details.