In today’s digital world, the smartphone has become not just a means of communication, but a store of confidential information, including access to bank accounts through the Internet. SMS-That's why it's a security issue. SIM-The installation of a personal identification number (PIN) creates a first and critical barrier for attackers who may try to steal your number or use it for their own purposes.
Many users neglect this setting, relying only on locking the screen, but it is a flawed security strategy: If the device is stolen or lost and the screen is unlocked (or bypassed), then it is a misguided security strategy. SIM-A passwordless card will give you access to your number on any other phone, and in this article we will discuss in detail how to activate this protection in the shell. MIUI HyperOS, what codes to use and what to do in case of blocking.
The setup process takes literally a minute, but ensures the long-term security of your digital assets. We will consider the regular tools of the system that do not require the installation of third-party software or obtaining root rights.
Why do you need protection? SIM-maps on Xiaomi
Substantive function PIN-The code is to encrypt access to the SIM card itself, not the phone's operating system, which means that even if you take a chip out of your Xiaomi Redmi or Poco and insert it into any other device, without knowing the code, it won't work. This effectively turns a SIM card into a useless piece of plastic for someone who doesn’t know the secret set of numbers.
In addition, protection against unauthorized use saves from financial losses, and attackers often steal smartphones for the sake of access to the Internet. SMS-The presence of a password on the SIM card blocks the ability to receive these messages on someone else's device, giving you time to remotely lock the number from the operator.
It's important to understand the difference between security codes. The default PIN (usually 0000 or 1234) is often listed on the plastic card holder that is issued when you buy a SIM card. It's this code that needs to be changed to unique when you first set up, because the standard values are known to many and are easily matched. Ignoring this step leaves the door to your digital life ajar.
It’s worth noting that modern communication standards and regulatory requirements are gradually tightening security rules. Operators recommend and sometimes require activation of protection to prevent fraud. On Xiaomi devices, this functionality is implemented as deeply as possible in the system, allowing you to manage it without unnecessary complications.
Preparation for password installation: important nuances
Before you go directly to the settings in the MIUI menu, you need to make sure you're ready for the procedure. The most important thing is to know the current PIN set by the operator. If you've never changed the factory settings, it's probably a standard combination of 0000 or 1234. You can find the exact value on the plastic card that came with the SIM card.
If the card is lost and you don't remember the code, don't try to guess it by squeaking it. Three mistyping attempts will result in the SIM card being blocked and the request is made. PUK-This is a more complex unlocking procedure, requiring you to contact the operator or enter a long code from your personal account.
⚠️ Warning: Entering the wrong PIN three times in a row will block the SIM card. PUK-The code ten times will lead to a complete and irreversible blocking of the SIM card, after which it will have to be replaced by the operator.
Also, before starting the procedure, make sure that your Xiaomi battery is sufficiently charged. Although the setup process is not energy intensive, suddenly turning off the smartphone while recording new security settings can cause a software failure in the communication module. 20-30%.
It is recommended to write the new code you have invented in advance to a safe place (notebook, password manager) so as not to forget it in case of prolonged unused phone.
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Write down a new one. PIN-Do not store it in your phone's notes without additional protection, use a paper carrier or a specialized password storage application.
Step-by-step: activation PIN-code-in MIUI HyperOS
The interface of the MIUI shell and the new HyperOS may differ slightly from Android to Android, but the logic of the location of the security settings remains the same. Below is a universal sequence of actions that is relevant for most models Xiaomi, Redmi and Poco.
First, you need to open the main settings menu. Find the gear icon on your desktop or notification curtain. In the list that opens, look for the password and security section. In newer versions of firmware, it may be simply called Passwords and Security or have a separate category called Privacy Protection.
☑️ Algorithm of protection installation
Next, you'll find the SIM-specific item, which is usually called SIM-specific privacy or SIM-card settings. Inside this menu, you'll see a Secure SIM-card switch, activate it, and the system will immediately request the current PIN.
After successfully entering the factory code (e.g. 0000), the system will suggest you to come up with a new one. Enter the desired 4-digit combination and confirm it by re-entering it. From now on, every time you reboot your phone or retrieve the SIM card, you will need to enter this new code.
For dual-symbol devices, the procedure is repeated for each card separately. Please note that the menu will display SIM 1 and SIM 2, and the settings for them are independent, this allows you to set different passwords or leave one of the cards unprotected if necessary.
How to change or disable a password request
There are different situations: you may have forgotten the complex code you installed, or you may have lost the need to protect it (though this is unlikely), but in any case, the function is managed in the same menu as the activation, and you must first unlock the SIM card with the current password to change the code.
On the privacy menu SIM-cards after the protection is activated, additional items become active. PIN-The system will ask you to enter the old ID code and then double-new. Try not to use obvious combinations like date of birth or sequence 1234, 1111.
If you firmly decided to disable the request for a password, just translate the switch to Protect SIM-The system will require you to enter the current PIN to confirm the action, and then when you reboot the phone, the password will not be asked.
⚠️ Attention: Disconnection PIN-This code reduces the security of your number, and only do it in extreme cases and only if you are confident in the physical safety of your Xiaomi device.
Some users are faced with a situation where the phone stops remembering the code entered and asks it every time the screen is turned on, this is a bug of the MIUI software. In this case, the full cycle helps: disable the protection, restart the phone, then turn on the protection again and come up with a new code.
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Change of change PIN-Code is the best security practice if you used a standard factory password, as it is easily recognizable by attackers.
Access problems: PUK-code-free
The most common problem users face when setting up is accidentally blocking the SIM card. As mentioned earlier, three incorrect PIN inputs lead to a request. PUK-Personal Unblocking Key is an eight-digit code that is no longer selected by the user but is issued by the carrier.
Where to find out. PUK-The easiest way to do this is to look at the plastic card that came with the SIM card when you bought it, and the code is often listed under the security layer or printed next to it. PIN. If the card is lost, the code can be found in the subscriber’s personal account on the operator’s website or obtained through the support service.
The process of unlocking on Xiaomi is as follows:
- 📱 On the lock screen will appear a message about the request PUK-code.
- 🔢 Enter the 8-digit code received from the operator.
- 🆕 The system will suggest to come up with a new PIN code (4-8 figure).
- ✅ Confirm the new code by re-entering.
After a successful procedure, the SIM card will be active again, and you can use the connection. It is important to write the new PIN right away so that you do not repeat the procedure again. PUK-code 10 times, the SIM card will be blocked forever, and you can only restore access to the number by re-releasing the SIM card in the operator’s cabin with the number saved.
What to do if PUK-The code doesn't work either?
Table of codes and security statuses
To organize information about the types of codes and their purpose, it is convenient to use a summary table. This will help you quickly navigate what code is required in a particular situation on your Xiaomi device.
| Type of code | Length | Appointment | Where to find out. |
|---|---|---|---|
| PIN | 4-8 digits | Daily unlocking of the SIM | It is set by the user (factory on the map). |
| PUK | 8 digits | Unlocking after 3 PIN errors | On a plastic card, in a personal office |
| PIN2 | 4-8 digits | Access to special functions (rarely) | Factory on the map (often 0000) |
| PUK2 | 8 digits | Unlocking after PIN2 errors | On the operator's plastic card |
Note that PIN2 and PUK2 codes are rarely used in modern Xiaomi smartphones, mostly for older features like limiting call lists or controlling charging, which carriers no longer support, but the system can request when trying to access certain sections of the phone's menu.
If the phone requests PIN2 and you don't know it, try the standard 0000 or 1234 combinations. If they don't fit, it's best not to experiment and leave this feature unattended, as it's not required for basic phone and internet operation.