How to activate a SIM card on Xiaomi: the complete guide

Modern smartphones Xiaomi, Redmi and POCO They're famous for their functionality, but the initial setup process can raise questions for beginners. Often, users are faced with a situation where, after installing the card in the tray, the device does not see the network or requires additional actions to get started. SIM-Cards are the foundation of stable communication, fast Internet and correct operation of all services.

In this article, we will take a look at all the steps of connecting a SIM card to your device. You will learn about the physical features of slots, the nuances of MIUI and HyperOS software, and how to solve common errors. Incorrect settings can lead to no access to the network or increased traffic consumption, so it is important to follow proven algorithms of actions.

We will look not only at standard scenarios, but also at complex cases that require manually configuring access points, and we will focus on security and dual-SIM card features, as this is one of the most sought-after features in the Chinese manufacturer’s ecosystem.

Physical installation and contact verification

The first step is always to physically fit the communication module properly, depending on your Xiaomi smartphone model, the tray can be combined or separate.

Use only the original paper clip or a special key included in the delivery.Severe pressure or the use of foreign sharp objects can damage the tray extraction mechanism, which in the budget models of Redmi and Poco is often made of thin plastic.

• 📱 Make sure the notch on the SIM card matches the tray shape.
• 💧 Wipe the card contacts with a soft dry cloth before installation.
• 🔒 Insert the tray until the characteristic click without applying excessive force.

Once installed, turn on the device. If the system does not recognize the card immediately, try restarting the device. In some cases, you need to remove the protective film from the contacts of the new card, as the factory coating may prevent the connection.

If you use nano-SIM to micro-SIM adapters or standard size, make sure they are quality. Cheap adapters often have shifted contacts, which leads to unstable communication module operation and constant connection breaks.

Primary configuration in MIUI and HyperOS

Once you load MIUI or the new HyperOS, the device will automatically try to determine the operator's settings. The welcome screen may suggest setting up the Internet and multimedia messages. It is not recommended to opt out of automatic settings, as this saves time and reduces the risk of errors.

For manual control, go to the settings menu. The path usually looks like this: Settings. → SIM-This shows the status of each card installed, and if you see "No Network" or "Emergency Calls Only," you need further diagnosis.

⚠️ Note: If the system requests PIN-If you turn on the code, you enter it carefully. Three incorrect inputs will block the card, and you will need to enter it. PUK-code that must be requested from the operator.

In the same section, you can assign a default card for voice calls and mobile internet. For 5G-enabled models, it’s important to manually select your preferred network type if the automatic selection isn’t working properly in your area.

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Use the "Game Acceleration" function only for the game SIM card so that the background downloads on the second one do not affect the ping.

Make sure to check if data roaming is activated if you are located abroad or in a region with coverage from another operator, without which the Internet will not work even if voice communication is present.

Manually configuring APN access points

The most common reason why a SIM card is installed but the internet is not working is incorrect APN (Access Point Name) settings. Operators periodically change settings, and automatic sending of settings may not come or be incompatible with Xiaomi firmware.

To create an access point manually, go to Settings. → SIM-maps and mobile networks → (Select a SIM card) → Access points (APN). Click the "New Access Point" button or the plus icon in the upper right corner of the screen.

You need to enter the data provided by your operator here, usually you only need to fill in the fields "Name" and "Access Point (APN)". Other parameters, such as proxy, ports, username and password, are often left empty or filled in automatically.

Once you have entered, be sure to click the menu (three dots) and select Save. Then activate the access point you created by ticking it next to it, and without saving, the changes will not take effect, and mobile Internet will not work.

If the Internet doesn't come on right away, turn on and off flight mode, this will force the device to re-register on the network with new parameters, and in rare cases, you may need to completely reboot the smartphone.

Solving problems with registration on the network

A situation where the phone says “No network” or “Not registered on the network” can be caused by a software failure or frequency incompatibility. Xiaomi smartphones, especially global versions, support a wide range of frequencies, but in some regions there may be conflicts.

Try resetting your network to factory settings. This action won't delete your personal data, photos or apps, but will return your Wi-Fi, Bluetooth and mobile settings to their original state. Path to reset: Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth.

⚠️ Note: After resetting your network settings, you will need to re-enter passwords from all saved Wi-Fi networks and re-enter Bluetooth devices.

It is also worth checking whether the SIM card is blocked by the operator due to suspicious activity or unexpired payment. USSD-request.

In some cases, switching network mode helps. Go to Preferred Network Type and select LTE Only or 3G Only. If one mode is connected, then the problem is covering a specific communication standard in your local area.

Working with two SIM-map

Most Xiaomi devices feature a hybrid or full-fledged dual slot. The second SIM card is usually activated automatically, but management requires attention.

On the menu. SIM-You can assign cards and mobile networks to determine which card is used for default calls and which is used for the Internet. There is also a Constant Ask feature that will display the card selection dialog before each call.

• 📞 Set the card with the best coverage in your area as the primary for calls.
• 🌐 Set a tariff with a large amount of traffic for data transfer.
• ⚙️ Disable the second SIM card programmatically if it is not needed to save charge.

It is important to consider that when you actively talk on the first SIM card, the second one can go into Unavailable or Occupied mode if VoLTE is not enabled.

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VoLTE allows you to conduct a voice conversation and simultaneously use 4G Internet on the second SIM card without switching to 3G/2G.

For frequent travelers, the location-based SIM card switching feature is useful, and you can set the rule in your settings: "Use SIM 2 for the Internet when connected to your home Wi-Fi" or similar automation scenarios.

Security and SIM locking

The security of your SIM card is directly related to the safety of accounts in messengers and banking applications. PIN-It is recommended to change the standard code (usually 0000 or 1234) to a unique code known only to you.

If you enter incorrectly three times PIN-The code, the card will be blocked and you will need to PUK-It's 8 digits long, and it's on a plastic card that came with a SIM card, or in the operator's personal account.

Entering PUK-code:


1. Enter the 8-digit code.




2. Invent a new PIN- code 4-8 digits ).




3. Confirm the new PIN-code.

Be careful: ten times incorrect input PUK-The code causes irreversible blocking and damage to the SIM card. It will be impossible to restore it, you will have to get a new one with the preservation of the number.

⚠️ Warning: Never keep it. PUK-code in your phone's notes or in the cloud without encryption.

Also in the security settings MIUI You can find the lock function. SIM-This will prevent your card from being used in the stolen phone, even if the attacker tries to insert it into another device.

Frequently Asked Questions (FAQ)