Losing a smartphone or suddenly stealing a device is always a stressful situation that requires immediate and decisive action. Owners of Xiaomi, Redmi or Poco devices need to know the algorithm for locking a SIM card to prevent unauthorized access to banking applications and personal data. Procrastination in such cases can cost you money and confidential information, so the speed of reaction here is crucial.
There are several effective ways to restrict access to a number: from simple input PIN-We'll look at all the options available, including the hidden capabilities of the system. MIUI And HyperOS, which will help secure your digital profile, and it's important to understand the difference between locking your phone and locking your subscriber number.
In this article, we will discuss the technical details of the procedure in detail so that you can choose the most appropriate method of protection. Whether the device is in your hands or already lost, you will find here the current instructions. The fastest way to lock in case of loss is to call the operator, as this instantly cuts off voice communication and access to SMS.
Emergency lock through request codes
The most affordable method if you have the phone in your hands, but you want to temporarily limit its functionality or protect it from children, is to use it. USSD-The carriers provide standard codes that work on any device, including Xiaomi. Querying a specific query puts the SIM card in a standby state. PIN-code-in.
To activate the protection, you need to open the Phone app and dial a command specific to your operator. For example, for many operators, a universal code **04* is running, followed by the current pin code and a new pin code. However, a more reliable way is to set a ban on outgoing calls through the settings of the smartphone itself, which does not require remembering complex combinations of numbers.
If you plan to transfer the phone to another person without removing the SIM card, this method will allow you to keep the number active, but locked for use in the wrong hands. PIN-Without this code, making calls or accessing the Internet will be impossible.
💡
Write it down. PUK-Your SIM card code is securely located separate from your phone. PIN-The code will block the card permanently, and it will be possible to unlock it only through PUK.
⚠️ Attention: Never enter PUK-Ten wrong attempts will cause physical damage to the SIM card chip, and the only way to restore the number is to re-release the plastic in the operator's cabin.
Blocking through MIUI and HyperOS interface settings
The MIUI shell and the new HyperOS provide convenient tools for managing SIM cards directly from the settings menu, ideal for quickly disabling a second SIM card or temporarily disabling access to the network without removing the tray. The interface allows you to flexibly adjust the settings of each SIM card installed separately.
To use this feature, go to Settings, then select SIM cards and mobile networks. Here you will see a list of all active cards. The Use SIM switch allows you to instantly disable the communication module. In this state, the phone will not register with the operator's network, which is equivalent to a software lock.
You can also set up roaming restrictions or choose your preferred network type on this menu, and if you lose your phone, this method won't help, unfortunately, because it requires physical access to the unlocked screen, but for parents who control their children's use of the gadget, it's a great tool to temporarily limit communication during school.
It is important to note that the software shutdown in Xiaomi settings is reset after the device is fully restarted unless a request is set. PIN-So for the best protection, it's recommended that you combine this with a password on the SIM card itself, and that creates a double barrier for strangers.
Remote lock through the operator
When a smartphone is lost or stolen, the only solution is to call the carrier, and locking it at the operator's network level makes it impossible to use the number on any device, even if the attacker has time to remove the SIM card and insert it into another phone, which is the most radical and effective measure.
You can contact support via the operator's personal account on the operator's website, through the operator's application (if you have access to Wi-Fi), or by calling from another number, you will need to name the code word set at the conclusion of the contract, or answer security questions to identify the identity, and after confirmation, the operator will immediately suspend service of the number.
Once blocked, all incoming and outgoing calls, as well as SMS and mobile Internet, will be unavailable.The phone that inserted your SIM card will display a message about a lack of network or registration error, which gives you time to calmly change passwords in banking applications and instant messengers associated with this number.
| Operator. | Method of blocking | Contact number | Duration of the lock |
|---|---|---|---|
| MTS | Personal Cabinet / Call | 0880 | Before unlocking by the owner |
| MegaFon | Appendix/Site | 0500 | 7 days (automatic) |
| Beeline | Personal office | 0611 | On the application |
| Tele2 | Website/Office | 611 | Until unlocked. |
⚠️ Note: After the operator locks the number, access to SMS-The password recovery codes in social networks and banks will be completely closed. Make sure you have backup authorization methods in advance.
Using Google Find the Device Service
The Android ecosystem offers a powerful built-in data protection tool that works even without access to the phone’s menu.Find My Device allows you to remotely lock your smartphone screen, display a message on it and, most importantly, prevent the use of a SIM card to access data, although it does not turn off the network itself.
To use this feature, you need to have a lost Xiaomi logged in to Google account, the Internet is turned on and geolocation is active. Going to google.com/android/find from any computer or other phone, you can see the location of the device on the map. From the control menu, select the option “Block the device”.
After activating the lock, your message and number will appear on the screen. PIN-While the SIM card will technically remain active for incoming users, an attacker will not be able to use the phone or reset it without your Google account.
☑️ Checking before loss
It's worth noting that this method doesn't block the SIM card from the operator, so it's theoretically possible to intercept SMS if the phone is unlocked by someone who knows your screen password. So the combination of locking through the operator is mandatory for complete security.
IMEI Blockage: Radical Measures
If the phone is stolen and you don't expect to be returned, you can initiate a lock using a unique IMEI ID, which is assigned to the phone's hardware module itself, not the SIM card, and IMEI locks are entered into carrier databases, after which the device becomes useless for use in cellular networks, regardless of the SIM card inserted.
This procedure requires a police report of theft, with a phone box or warranty card, which includes an IMEI. Police request telecom operators. In some countries, there are common bases where you can apply directly through the communications regulator's website, but in most cases, law enforcement is required.
Once blacklisted, the phone stops catching the network, and even if the thief replaces the SIM card, the device will not be able to register with any carrier, which makes the theft economically impractical, but it is worth remembering that it is almost impossible to unlock the IMEI legally, so only use this method in case of real theft.
Where can I find IMEI without a phone?
It is important to distinguish between SIM card lock and phone lock: SIM card lock protects your number and money in your account; IMEI lock protects the device itself from resale and use on networks; for maximum efficiency, both methods must be used simultaneously.
Protection against fraudsters and social engineering
Often users themselves become victims of fraudsters who, under the guise of bank employees or police, ask to dictate the code from the person who came to the bank. SMS It's called a security service to lock your card, and remember, no operator or bank employee will ever ask you. PIN or PUK-SIM card.
If you get a message about blocking a SIM card asking you to click on a link, it is phishing. SMS-Always check the source of information through official applications of operators.
There is also a risk of SIM swaps, where fraudsters, having your passport data, restore the SIM card to themselves. To avoid this, never store a passport photo in the cloud without protection, and do not transfer passport data to dubious sites. If you suspect that a third party is trying to restore your SIM card, immediately block the number.
💡
The main protection against fraudsters is to never report codes from SMS or follow suspicious links, even if they look like messages from a bank or operator.
⚠️ Attention: If you have received SMS If you say that your SIM card is allegedly blocked and you are asked to call the number indicated - do not do this.