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Caller ID has been around for many years, and it is now a pretty standard part of any cell phone calling. In the early days, you might buy a special home phone or attached device to get caller ID functionality, and, almost as if by magic, the display would show the name of the person calling your landline.

These days, it is much easier, but there are still different messages that might pop up besides numbers that we simply do not recognize when a call is coming through. Some users might get calls that show on their screens as “anonymous,” but they might have an unknown call at other times.

It’s a good idea to get familiar with the difference between these two kinds of calls, what they mean, and what you might be able to do in order to block them if you choose.

Depositphotos_349021524_S Phone call from unknown number late at night

What’s the Difference Between Anonymous and Unknown Calls?

We’ve all been in situations where we are simply too busy to take a particular call when it is coming through on our phones. It happens regularly, but some people may notice that their missed call logs display different identifiers for different numbers.

Aside from just showing you a number you don’t recognize if it is not in your contact list somewhere, you might see the header for the caller listed as either unknown or anonymous. While these are similar, they are different enough from each other to be distinctive.

When you get or miss a call from a number that is unknown, it means that the network carrier was not able to get identifying information from the originating number at the time that the call was made.

In short, the telecom operator is not able to interpret the number using meaningful identifiers, and it will show up as “unknown” because of this.

In most cases, this means that certain restrictions are preventing the carrier from displaying the identifying information, or they might be restricted in how they can interpret it at all.

Unknown caller IDs mean that the number was private at the time that the call was made, but it could also mean that there was simply a network hitch that prevented the carrier from obtaining the identifying information.

Calls can pass through more than one point before reaching their destinations, and they can also get somewhat “glitched” during their travels. In some of these cases, the calls may end up as unknown once they get to where they are supposed to go.

Although a first reaction from many people might be to assume that the call is spam or malicious in some way, this can be the result of an error as much as it could be intentional. However, it is also true that certain call centers or international businesses may show up as unknown numbers when calling people.

Conversely, an anonymous number is one that the caller has chosen to hide from the recipient intentionally.

There are ways for anyone to make their numbers appear private once a call is made. The person making the call has blocked the number from coming up on caller ID settings for your phone at all.

With anonymous calling, there is less chance that there is a hitch in the system resulting in the carrier not obtaining identifying information. You can think of anonymous calls as private versions of numbers that are quite intentional on the part of the callers.

What Is the Difference Between an Unknown Caller and an Unavailable Number?

To recap from the previous section, an “unknown caller” is a call that comes from a number that your mobile carrier could not register.

On the other hand, there can be several reasons that an “unavailable number” pops up.

If a call comes from an unavailable number, the most common reason would be the call is coming from an area where the service provider cannot retrieve a phone number.

In some cases, a call might be designated as “unavailable” on a phone’s caller ID because it is placed from an area or region from which the wireless service provider or phone company cannot retrieve a phone number.

Other reasons could include:

  1. The phone is turned off: If a phone is turned off, the number will be unavailable because the phone cannot receive calls.
  2. The number is blocked: If someone has blocked your number, their phone will not ring when you call, and you will hear that the number is unavailable.
  3. The caller uses a private number: Some people choose to make their phone number private to protect their privacy. When they call, their number will appear as unavailable.
  4. The account is suspended: Cellular carriers can and do suspend accounts behind in payments, and such a suspension causes the number to be temporarily disabled.

Depositphotos_432820626_S Fraud call 3D illustration concept

Why Is a Private Number Calling Me?

Now that you know some of the major differences between the kinds of private calls you can get, you might wonder about some of the reasons a private number might choose to contact you.

Many people assume that there is no good reason for any private number to give them a call. It is certainly true that many of the calls people can’t identify turn out to be spam, robotic messages that make little sense, or outright scams that might seem too good to be true at first glance.

With all of that in mind, you may wonder if there is any good reason for a private number to call you. There are some methods by which anyone can set an outgoing call to appear as private when you receive a notification on your phone.

That means that a private number could be an individual that you know, or one who knows you, and they have set their number to appear as private for their own reasons.

While this may not be the most likely scenario, we would be remiss if we did not mention it here. Some people do prefer privacy when making a call, and it may have nothing to do with you specifically.

Some private numbers may also call to offer specific services that they think you might need. This can happen in cases where you give out your phone number a lot online.

While many legitimate sites need your phone number for contact purposes in order to get in touch with you if there is a problem, it is also true that there is a risk of giving your phone number out to unscrupulous callers who might bother you.

If you find that you’re getting an increase in private calls after signing up for online services through various vendors, you may be getting calls from people who got your number this way.

Who Calls From Private Numbers?

We mentioned that anyone has the capability to call from a private number.

However, there are some instances where this type of calling will be more likely than others. It isn’t usual for close friends or people you know to decide to call you from a private number, for example.

Some businesses may choose to call from private numbers even when they are offering legitimate services. There could be various reasons for this, and they may be trying to keep their own spam calls down to a minimum. Individual people who appear to be private might be trying to do the same thing.

Conversely, many call centers that are engaged in telemarketing will choose to call from private numbers. One way a person might screen calls and decide if it is likely that they know the caller is via an area code or other identifying information.

By hiding this through private calling, it is possible that telemarketers expect to see an uptick in people who will answer the calls.

On a related note, it is also possible for call centers that are not located in your area to look as though they are local when you get a call from them, although this is not the same thing as a private call.

Some bill or collections agencies may also call from private numbers. While this is possibly for intimidation purposes, it can also make it harder for you to figure out how to block their calls effectively. This can increase their chances of being able to contact you again later if necessary.

These are not the only businesses that might do this regularly, but they are some of the most common ones. Be aware, though, that some calls relating to credit or debt can just be scam calls that are not from legitimate businesses, too.

Depositphotos_178018500_S Blocked red rubber stamp

How Do I Block Unknown Calls? (iPhone & Android)

Now that you know a bit more about private, unknown, or anonymous calling, it’s time to figure out just what you can do about it. There are ways to block unknown numbers on both Android and Apple devices.

The methods here that we will show you can set your devices to block all unknown calls that come in. Note, however, that it doesn’t necessarily mean they will always block everything.

Technology changes, and businesses find different ways to try to get through to your phone despite your best efforts. However, these methods should work for the majority of these kinds of calls.

On Android

For Android devices, you can:

  1. Go to wherever your ‘Phone’ app for calling is located and open it up.
  2. Once you’re inside, look for the icon with three vertical dots on it and select it to get to a menu that includes the app’s ‘Settings’.
  3. From here, you can tap on ‘Block numbers’, and you can then toggle the setting for blocking all unknown calls.
  4. In rare cases, an Android device may not have this setting, but there are apps that can facilitate it for you.

On Apple

If you have an iPhone and need to block unknown calls, you can:

  1.  Go to the ‘Settings’ app on your iPhone.
  2. From here, navigate to the ‘Phone’ app on your device. In this section, you’ll find a list of options.
  3. If you scroll far enough, you should see a heading that reads ‘Silence Unknown Callers’. Toggle this in order to activate it.
  4. Before you do this, make sure you have important contacts saved so that they can get through to you.



Both unknown and anonymous calls can be annoying, although there are occasions where you might get a legitimate call from numbers that show up on your screen like this.

They are slightly different ways of accomplishing similar ends, and it is a good idea to know how they work so that you can avoid them. If you find that you are getting an abundance of these calls, you can set your phone to screen for them automatically.