Rejecting calls from unknown numbers can be a mistake: what experts recommend

The explanation has to do with how security systems work. automated callscall centers and, increasingly, telephone fraud campaigns.

Every communication attempt leave a technical record: if the phone rings, if the call is disconnected immediately, if there is a busy signal or if someone answers. In that ecosystem, any user reaction can serve as confirmation that the number is active and in use.

In other words, not answering a call does not always equate to “closing the door.” For many systems, it may be a sign that there is someone on the other sidewhich returns to the number most valuable within databases commercial or directly fraudulent. From this validation, calls can increase in frequency or lead to new attempts, even from different numbers.

YOU’VE BEEN BLOCKING SPAM CALLS BADLY THIS WHOLE TIME.

Every time you reject a call, you confirm that your number is active.
The calls multiply.

This is what really works:

— Nona (@Nona_xai) January 9, 2026

The problem starts before the phone rings. When registering in online services, apps or digital platforms, the number may become associated with different profiles and end up circulating on commercial lists or data markets. There not only contact matters, but also how the user reacts. Every interaction—no matter how small—helps optimize future campaigns.

The general recommendation is clear: minimize any type of interaction. Do not return calls to strange numbers, do not talk to automatic systems, do not press keys for supposed cancellations and do not respond to messages that ask for confirmations. Even let the phone stop ringing without touching anything may be more effective than cutting manually.

Both Android as iOS They incorporate detection systems based on databases and user reports. Activating them reduces exposure to spam without the user having to decide what to do each time. There are also third party applications that reinforce this protection, although it is recommended to carefully review the permissions they request.

If you do not want to receive private calls on Android phones, you must follow these steps:

In addition, Android allows you to identify commercial or fraudulent calls in real time, displaying alerts on the screen before the user interacts. On many models, you can also activate the option Filter spam calls from Settingsso that the system automatically silences or blocks these contacts.

iPhones (iOS), meanwhile, have the function Silence unknown calls, that automatically sends numbers that are not in the phonebook to voicemail, without generating visible interaction. If you do not choose this solution, the following configuration will have to be carried out:

Beyond the specific blockade, there are structural actions: withdraw consents in services where the number has been leftregister in advertising exclusion registries and make complaints when a company fails to comply with regulations.

Although they do not offer immediate results, in many cases they attack the indiscriminate use of personal data, which, after all, is the root of the problem.

In a scenario of growing spam and telephone scams, an impulsive reaction can work against you. Reducing signals, avoiding interactions and relying on system filters makes the number less attractive to those who make a living by insisting. In this case, Going unnoticed can be the most effective strategy.