Xiaomi Mi 9: How much? SIM-The cards can be installed and how it works?

Xiaomi Mi 9 is the flagship of 2019, which is still a hot choice thanks to its powerful hardware and affordable price in the secondary market. SIM-Is it possible to use two SIMs and a memory card at the same time? What about eSIM? In this article, we will go through all the nuances, including hidden restrictions and life hacks for setting up.

Spoiler: The Mi 9 has a hybrid slot, which is a limited one if you're planning to use two physical slots. SIM-But there are workarounds that we'll talk about below, and we'll also look at regional differences (e.g., Chinese and global versions are different!) and compatibility with modern communication standards such as VoLTE and other technologies. 5G (Yes, despite the lack of a module. 5G In Mi 9, it's important to work with the sims).

Technical characteristics of the slot SIM-Maps in Xiaomi Mi 9

Xiaomi Mi 9 is equipped with a hybrid card slot that supports the following combinations:

• 📱 Two nano-SIMs (without MicroSD) are standard modes for most users.
• 📱💾 One nano-SIM + MicroSD (up to 256 GB) – if memory expansion is given priority.

Important: simultaneous use of two SIM-It is a limitation of the hybrid slot architecture that is found in many flagships of the time (for example, in the Samsung Galaxy). S10 Huawei P30 Pro).

Let's take a closer look at this.

• 🔧 Type of slot: Nano-SIM (4FF) — the most compact standard for today.
• 🌍 Support for standards: GSM / WCDMA / LTE (before Cat.16 basic SIM).
• ⚡ Additional features: VoLTE, ViLTE (video calls by video) LTE), without support 5G.

Interesting fact: in the Chinese version of the Mi 9 (model) M1902F1G) The slot may have other frequency restrictions LTE, What affects the work of sims outside China (M1902F1A) lacking.

Hybrid slot: how it works and what restrictions imposes

The hybrid slot in the Mi 9 is a trade-off between the compactness of the case and the functionality. Let's get a sense of how it works and what it means for the user.

Physically, the slot is a tray with two nests:

1. The first slot is always for nano-SIM (main sim).
2. The second slot is either a second nano-SIM or a microSD (but not at the same time!).

Switching between modes is automatic: the smartphone determines the type of card installed.

• ⚠️ Priority SIM: If you put two SIMs in, the main one is the one in the first slot. 4G+ — Secondary SIM can only work in the mode 3G/2G.
• 🔄 Hot Replacement: MicroSD can be retrieved without rebooting, but SIMs can’t (reclaim required).
• 📶 Speed limit: Secondary SIM does not support carrier aggregation (LTE-A), Even if the main sim is connected to 4G+.

⚠️ Note: If you use two of these SIM-You can put in a microSD, and the second SIM will automatically shut down. It won't delete the data, but it will also delete the calls. SMS will be available only after the memory card is removed.

For clarity, we will give a compatibility table:

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If you are critically important two SIMs and memory card, consider buying Xiaomi Mi 9 Pro 5G — He has separate slots for two. SIM microSD.

Xiaomi Mi 9 eSIM Support: Myth or Reality?

The issue of eSIM support (built-in) SIM-The cards are often used by users who want to use two SIMs without physical cards. Unfortunately, the Xiaomi Mi 9 does not support eSIM at the hardware level.

This is confirmed by official documentation and tests of enthusiasts, even after updating the firmware to the latest version (MIUI 14) eSIM function does not appear. Xiaomi’s list of eSIM smartphones includes later models, for example:

• 📱 Xiaomi 12T Pro (2022)
• 📱 Xiaomi 13 Lite (2023)
• 📱 POCO F5 (2023)

If eSIM is a big deal for you, you’ll have to consider alternatives or use adapters (but that doesn’t guarantee stable performance!).

⚠️ Note: Some aftermarket sellers claim that the Mi 9 supports eSIM after "firmware" is a hoax - there is no hardware support and such manipulation can lead to loss of warranty or device blink.

How to set up two SIM-maps: step-by-step instructions

If you choose to use two physical SIM-Xiaomi Mi 9 cards, here’s how to set them up correctly to avoid connection issues.

Step 1: Installation SIM-map

Use a paper clip or a special key to remove the tray.

• 🔹 Cards inserted with gold contacts down.
• 🔹 SIM1 (The main one is in the first slot – this is critical for VoLTE.
• 🔹 Cards are trimmed to nano-SIM format (12.3 × 8.8 mm).

Step 2: Set up the parameters SIM

After the smartphone is turned on:

1. Go to Settings. → SIM-maps and mobile networks.
2. Select Names. SIM-cards to assign them labels (e.g., "Worker" and "Personal").
3. In the Mobile Internet section, indicate which SIM data-transmitting.
4. Activate VoLTE for the main SIM (If your operator supports this function).

Make sure both cards support your carrier’s frequencies|Check the balance on both SIM (Sometimes the second SIM is blocked at zero balance)|Disable "Select Network" for a stable connection|Reboot the smartphone after installing the cards-->

Step 3: Challenge management and SMS

V MIUI Flexible settings for working with two SIMs:

• 📞 Calls: You can choose which one SIM call by default, or ask it at each call.
• 💬 SMS: Similarly, it's chosen. SIM message-post.
• 🌐 Mobile Internet: Only One SIM It can be active for data transmission.

Important: If you have problems with connection on the secondary SIM, try:

##4636## → Phone Information → Select your preferred network type: LTE/3G/2G (auto)

Compatibility with operators: which SIM-The cards work better.

Not all. SIM-The cards work equally well in the Xiaomi Mi 9. Here’s what to consider when choosing an operator:

1.VolTE and ViLTE support

VoLTE functions (voice by voice) LTE) ViLTE (video calls) is only available on the main SIM (SIM1). For their work:

• 📶 The operator must support these technologies (in Russia: MegaFon, Beeline, Tele2, MTS).
• 📱 The settings should include the call option LTE (Settings → SIM-map → Challenge LTE).
• 🔄 Sometimes you need to update the operator's service profile (comes automatically or on request via the operator's service profile). USSD-team).

Frequency LTE

The Mi 9 supports a wide range of frequencies, but there are nuances:

• 🇷🇺 In Russia, there are ranges: B1 (2100 MHz), B3 (1800 MHz), B7 (2600 MHz), B20 (800 MHz).
• 🇺🇦 In Ukraine: B3, B7, B20.
• 🌍 In Europe/Asia: B1, B3, B5 (850 MHz), B8 (900 MHz).

Problems may arise with operators using rare ranges (e.g, B28 (700 MHz) in some countries. Check compatibility on FrequencyCheck before buying.

3. Restrictions for secondary SIM

Second second SIM-map (SIM2) the following limitations:

• ❌ No support for VoLTE – calls will go 3G/2G.
• ❌ No carrier aggregation (LTE-A) — maximum speed is limited ~150 Mbps.
• ❌ It is not possible to use it for mobile Internet, if the main SIM already connected to 4G.

⚠️ Note: If you travel frequently, be aware that roaming may not work smoothly on a secondary route. SIM. Some carriers (such as T-Mobile in the US) block roaming for devices with hybrid slots.

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For maximum internet speed and stable calls, always use the main slot (SIM1) main SIM-map.

Frequent problems and their solutions

Even with the right setup with two SIM-Mi 9 can get into trouble with maps, and we'll look at the typical situations and how to fix them.

1.The second is not defined. SIM-map

If the smartphone does not see SIM2, try:

• 🔄 Reset the device.
• 🔧 Check if the card is inserted correctly (sometimes it shifts when installed).
• 📶 Manually select the operator in the Settings → SIM-map → Choice of network.
• 🛠️ Update the firmware to the latest version (in older versions) MIUI There were bugs with hybrid slots).

2. the network on one of the SIM

This is a common problem when using two sims.

• 📡 Turn off Auto Network Selection and fix the mode Only LTE basic SIM.
• 🔋 Check if it's discharged. SIM-card (some operators block it at zero balance).
• 📱 Reset network settings: Settings → System system → Resetting settings → Resetting Wi-Fi, Mobile Network and Bluetooth.

3. mobile internet does not work on the second SIM

The Internet only works through SIM1. To reconfigure:

1. Go to Settings → SIM-cards and mobile networks → Mobile Internet.
2. Choose. SIM2 as the primary means of data transmission.
3. Make sure that the operator has activated the data service for this SIM.

If the internet doesn’t work, check it out. APN-setting:

Settings → SIM- Maps and Mobile Networks → Access Points (APN) → [Select operator]

Conflicts between SIM microSD

If you are frequently switching between two modes SIM" and "SIM + MicroSD, there may be errors to avoid problems:

• 🔄 Always turn off your smartphone before changing your cards.
• 💾 Formatting MicroSD in FAT32 exFAT (NTFS unsupported!).
• 📱 After replacing the cards, perform Reboot, not just remove/insert the tray.

Alternatives: What to do if you need two SIM microSD

If the Mi 9 hybrid slot doesn’t suit your needs, there are a few workarounds:

1. Wireless data transmission

Instead of microSD, you can use:

• ☁️ Cloud storage (Google Drive, Mi Cloud, Yandex Disk).
• 📶 FTP-Wi-Fi server (applications like Solid Explorer or Wi-Fi server) FX File Explorer).
• 🔗 OTG-drive-storage USB-C).

Adapters for SIM + MicroSD

There are adapters that allow you to insert MicroSD into the slot SIM2, It's still possible to use two sims:

• ⚠️ This is an informal decision that could cause damage to the slot.
• 📶 Communication quality may deteriorate due to poor contact.
• 🔧 Careful installation is required (risk of bending contacts).

An example of such an adapter: Dual SIM + MicroSD Tray for Xiaomi Mi 9 (sold on AliExpress).

3. Use of the second telephone

If you are critically important two SIMs and expansion of memory, consider:

• 📱 Second smartphone (e.g. budget Redmi for second) SIM).
• 📞 SIM-boxing (device for remote connection of the second SIM via Bluetooth).
• ☎️ Virtual SIM (Services like Google Voice or Dingtone).

The latter option is suitable for calls, but not for SMS (What may be critical to bank notifications).

FAQ: Answers to popular questions