I am convinced that your phone has ever rung and you have seen that a private or hidden number appeared on the screen. These calls can be a real nuisance because they are usually people trying to sell us something, but they can also be jokes or some well-calculated scam attempt. We also have the option of being able to hide our number when calling, but can you know who is calling with the hidden number?
In this article we are going to explain both how to hide our phone number when calling as well as the system that exists so that the call appears hidden from the other person. In addition, you will also be able to see some numbers that should not be called in secret.
How to hide who’s calling
The reality is that anyone can make their number appear hidden from the person they are calling. To do it once, just enter a prefix before calling another person, and that prefix is almost always the same, except on a very specific occasion. If we call from landline to landline, or from mobile to mobile, we will only have to enter the prefix #31# before the other person’s number. If, for example, we want to call 111222333, we only have to dial #31#111222333. The difference is when we call from landline to mobile, we must enter 067 instead of #31#. It’s that easy.
If you don’t want to have to do this every time you make a phone call, there is a way you can use on your mobile phone to always hide your ID, both on Android and iOS. On Android phones we will have to follow the following steps:
- Open the phone application of your mobile.
- Look for the settings or call options option.
- Choose the “More” or “More settings” option depending on the one that appears.
- Select the “Issuer ID” option and click on hide number.
In the case of iOS, the process is quite similar, although since the operating system is somewhat different, we will have to do some steps that differ a little from the previous ones. To do this, follow these steps:
- Open your iPhone settings.
- Head to the bottom.
- Select the Phone option.
- Click on the “Show caller ID” option.
- Uncheck the box.
This is how caller ID works
When we introduce the prefix that we have shown you a little above to call, our identification number, which is known as Callin Line Identification (or CLI) is transmitted by the operator that originates the call. Transit operators to the destination operator may not alter this information in any way, unless they have express authorization from the Secretary of State for Telecommunications and Digital Infrastructures.
In addition to this CLI marker, there is also the Calling Line Identification Restriction (or CLIR) marker, which will always be active when the person making the call has originated it by hiding their identity with the steps that we have shown you above. What does this mean? That both the origin operator and the transit operator and the final operator know which telephone is the one that is calling at all times.
We must take into account, therefore, that the operators store this information for themselves, although we as users do not know it. This information is stored in case the hidden call is being made to commit a crime, in which case the operators will give the information to the security forces when they are claimed.
Does it appear on the invoice?
Something worth noting is the phone bill. As we have said several times before, hidden numbers are nothing more than phone numbers to which a prefix is added in front. These are not registered on the telephone of the person receiving the call, but as we have seen, the telephone number is registered with the operators when the telephone number passes through them.
So, can the hidden number appear on the invoice? Keep in mind that telephone bills do not usually collect the telephone numbers of the people who call us, collecting only those that we call. If we are the ones who call in a hidden number, we will see the call reflected in the invoice as if we had called without any type of prefix or blocker of our identity.
Beware of calling these numbers in secret
One thing that should be mentioned separately is that our hidden number will not always be hidden when we use it. The Resolution of October 30, 2001 specifies that the operators have the obligation to suppress the CLIR dialer and show the number that is making the call in all cases when the person is calling a series of numbers related to the security forces and state emergencies.
We are referring, of course, to numbers such as the emergency number (112), the police or the fire department, just to give a few examples. In fact, some of these entities may also receive information on the geolocation of the phone that is making the call based on the mobile antenna that provides service to the user, so your location could also be revealed.
Is it possible to know who is calling?
We come to the key question. Is it possible to know who is calling? The truth is that no. Despite the fact that the operators do record the numbers that pass through them, this information never reaches the end user of the call, so they are stored only in case they are needed in court due to the commission of some type of crime.
There are applications that promise to tell us who is calling us when we receive a hidden call, but most of them are not precise and limit themselves to informing us when a number that is not in our phone book calls us. So, unless you call one of the numbers that we have mentioned before, your identity will continue to be hidden.
