How to protect your mobile phone number from SIM exchange attacks

It is 2025 and mobile phone numbers are omnipresent. We use our phone numbers to register for websites and online services, retail and bank for social media and health suppliers. You can use your phone number to reset a forgotten password, and even to receive two -factor authentication codes to connect to your accounts.

But if someone can steal your phone number, you can effectively become you.

With your phone number, a hacker can start accessing your online accounts, and even inspire automated systems by thinking they are when they call customer service. A diverted phone number can sometimes be used to access the network of a company as if it were this employee, allowing access to sensitive files and data.

This is one more reason to proactively protect your phone number SIM exchangeA type of cyber attack that involves a hacker diverting the telephone number of a victim. The good news is that it is easier than ever to lock your number.

SIM exchange attacks generally occur when a malicious pirate calls a cell carrier imitating a specific customer. This pirate would use information they have found online, such as the name and date of birth of a customer, then ask a customer support representative to transfer or “carry” this number on a different SIM card or operator. As soon as this process ends, the person’s phone number will activate on a SIM card or a pirate controlled phone, allowing them to make calls and send and receive text messages as if they were the person they have just hacked.

Often, the only sign that this has happened is that the victim suddenly loses cell service for apparently no reason.

SIM exchange attacks operate a weakness of security checks within the internal systems of cell suppliers which allow support representatives to make modifications to customer accounts without necessarily obtaining the express authorization of the customer.

To fight against these types of identity and deception tactics, called Social engineering attacksThree main telephone operators in the United States – AT&T, T -Mobile and Verizon – have introduced security features that make it more difficult for malicious hackers to deceive a customer account, such as carrying their telephone number.

Take a minute or two to check the account of your phone operator; These features are often not very well published and may not be activated by default.

At & t

In July, AT&T presented its free wireless account locking safety function To help prevent SIM exchanges. The function allows AT&T customers to add additional account protection tilted on a parameter that prevents anyone from moving a SIM card or a telephone number to another device or account. The functionality can be activated via the AT&T application or via its online account portal by anyone man who manages the account, so make sure the account is protected by a single password and multi-factor authentication.

Mobile

T-Mobile allows customers to Prevent SIM exchanges And Block unauthorized number ports free of charge via their T-Mobile online account. The main account holder must connect to go to the parameter, such as activate or deactivate.

Verizon

Verizon has two safety features called SIM protection and number lockingthat prevent SIM exchanges and telephone number transfers respectively. These two features can be activated via the Verizon application and via the online account portal by the owner or the account manager. Verizon says that deactivating the functionality can lead to a period of 15 minutes before all transactions can be made – another backup to allow the legitimate account holder to reverse account changes.