How to insert it correctly SIM-Xiaomi Mi 8 Pro: instructions with photos and nuances

Why is SIM installation in Mi 8 Pro a question?

Xiaomi Mi 8 Pro is the flagship smartphone of 2018, which is still in demand thanks to the powerful hardware and camera with optical zoom. However, even experienced users sometimes face difficulties when first installing a SIM card. It’s all about the non-standard location of the tray, the lack of visible tags on the body and the fragile fixing mechanism. In this article, we will analyze the process from A to Z: from choosing the right SIM to checking the network after installation.

The feature of the model is a hybrid slot that supports either two nano-SIMs or one nano-SIM + microSD card (up to 256 GB). This means that if you want to expand the memory, you will have to sacrifice a second SIM card. Also, the Mi 8 Pro uses a tray with a spring mechanism, which can jam if you sloppy handle, we will tell you how to avoid breakage and what to do if the SIM card is not detected.

Important: the manual is suitable for all versions of the Mi 8 Pro (including versions with 6/128 GB and 8/128 GB), but does not apply to the Mi 8 or Mi 8 Lite - they have a different tray design. If you are the owner of the Pro version, read on.

What? SIM-The card supports Xiaomi Mi 8 Pro?

The smartphone works exclusively with nano-SIM (4FF format, size 12.3 × 8.8 mm). If you have an old SIM card (mini-SIM or micro-SIM), it will have to be trimmed or replaced in the cabin of the operator.

🔹 Bad contact – SIM card will periodically “fall out” from the network.
🔹 Slot damage – metal contacts can bend.
🔹 Overheating of the module - a loose fit leads to increased energy consumption.

Check your SIM card from the table:

SIM format	Size (mm)	Is it good for the Mi 8 Pro?	What do you do?
nano-SIM (4FF)	12.3 × 8.8 × 0.67	✅ Yes.	Install unchanged
micro-SIM (3FF)	15 × 12 × 0.76	❌ No.	Cut or replace
mini-SIM (2FF)	25 × 15 × 0.76	❌ No.	Replacement in the operator's cabin
eSIM	Virtual	❌ No.	Mi 8 Pro does not support

Note: If you use a 5G-enabled SIM card, the Mi 8 Pro will only work on 4G/LTE networks. The model does not support fifth-generation networks due to the lack of a corresponding modem (Qualcomm Snapdragon 845 is limited to LTE Cat.18).

📊 What format? SIM You're using it on your smartphone?

nano-SIM

micro-SIM

mini-SIM

eSIM

I don't know.

Where is the slot for SIM-cards in Mi 8 Pro?

The sim card tray in the Xiaomi Mi 8 Pro is on the left side (if you look at the screen with the front side), easy to miss, as it merges with the body and has no bright marks. Look for a small hole with a barely noticeable slot - this is the socket for extracting the tray.

In order not to confuse the slot with other elements (for example, with a microphone or speaker), focus on:

📍 Location: approximately in the middle of the left end, closer to the lower corner.
📍 Hole size: diameter ~0.8 mm (standard paper clip fits).
📍 Inscription: Some versions have engravings nearby SIM (But she might not be).

Don’t confuse the SIM slot with:

🔊 The microphone hole is located on the bottom end next to the USB-Type C.
📢 Dynamics is a grid on the bottom edge.
🔋 Charging indicator - a small light bulb to the right of the port.

💡

If you can’t find the slot, light the flashlight at an angle – the metal edge of the tray will reflect the light.

Step-by-step instruction: how to insert SIM-map

Before you start, make sure that the smartphone is turned off, which will prevent damage to the contacts of the SIM card and the communication module.

Prepare the tool. You'll need a paper clip (or a special key from Xiaomi's kit) If there's no paper clip, you can use a thin needle, but be careful - the plastic tray is fragile.
Unlock the tray. Put the paper clip in the hole until you feel a slight click. The tray will extend 1-2 mm — pull it with your fingers.
Set the SIM card. Put the nano-SIM in the appropriate slot with the gold contacts down. If you use two SIM cards, the second one is installed in the top slot (signed as SIM 2).
Put the tray back in place. Put it in smoothly, without skewing, until the characteristic click. If the tray is not fixed, check if the SIM card is lying correctly.

The layout of the SIM card in the tray, see below:

┌───────────────┐




│ SIM 2 │ ← Top slot (optional)




├───────────────┤




│ SIM 1 │ ← Main SIM card




└───────┬───────┘




│




Gold contacts down!

The tray is completely removed, without distortion |

SIM-map is trimmed to nano-format|

SIM card contacts are down |

Smartphone's off.-->

⚠️ Warning: If the tray is not fixed after installation, do not apply force. This may bend the metal guides. Check if dust or debris has entered the slots - clean them with a dry toothpick.

What to do if SIM-map is not defined?

If after installing the SIM card, the smartphone does not see the network, follow the following steps:

Reboot the device. Sometimes the communication module freezes when you first turn on.
Check the installation is correct. Remove the tray and make sure that the SIM card is flat and the contacts are not contaminated.
Activate the SIM card in the settings. Go to Settings → SIM-Maps and mobile networks and select an active SIM for calls / Internet.
Update your firmware. Outdated software can cause conflicts with new SIM cards. Check for updates in Settings → About Phone → System Update.
Reset network settings. In Settings → System → Reset settings → Network reset.

If the problem persists, try:

🔧 Insert SIM card in another smartphone – if it does not work there, the operator has a problem.
🔧 Wipe the contacts of the SIM card and tray with alcohol (voilless tampon).
🔧 Reverse the firmware to a stable version (if the error occurred after the update).

⚠️ If after all the manipulations the smartphone writes “No service” or «SIM-card is not supported, this may indicate a hardware malfunction of the communication module, in which case contact the service center - self-repair can lead to loss of warranty.

What do errors mean? SIM-map?

«SIM-card not inserted" - the tray is not fully inserted or the SIM card is not incorrect. "Incorrect PIN-Code" - lock after 3 failed attempts to enter (unlocked) PUK-operator-code). «SIM-card locked" - hardware lock (reflashing or replacement of the module is required). "Emergency calls only" - the SIM card is not activated by the operator or there is no network coverage.

How to set up two SIM-cards in Mi 8 Pro?

Xiaomi Mi 8 Pro supports dual SIM Dual Standby (DSDS) which means both cards are active but only one can work at the same time (e.g. if you are talking on SIM 1, SIM 2 will not be available for calls).

Open the Settings. → SIM-maps and mobile networks.
Choose a Name. SIM-cards for each (e.g., “Worker” and “Personal»).
In the Voice Calls section, specify the priority SIM card.
In the Mobile Internet, select which SIM card will be used for data transfer.
Activate the option to Enable data transfer during the call if you want to stay online on the second SIM.

Pay attention to the nuances:

📶 4G+4G Not supported – if one SIM card is running in LTE, the second automatically switches to 3G/2G.
🔄 Roaming – when roaming, data will be transmitted only through the main SIM card.
📞 Call restriction – if one SIM card is busy talking, the second is temporarily unavailable to incoming users.

Tip: If it is important for you to stay in touch on both SIM cards, set up a call forwarding to one of them. To do this, select Additional → Call forwarding in the SIM card settings.

💡

The Mi 8 Pro does not allow two nano-SIMs and a memory card to be used at the same time, and SIM cards are given priority – if you insert a microSD, the second SIM slot will be blocked.

Frequent Mistakes and How to Avoid Them

Even experienced users sometimes make mistakes when installing a SIM card in the Mi 8 Pro. Here are the most common ones and ways to prevent them:

Mistake.	Effects of consequences	How to avoid
Installation of SIM card "upside down"	Damage to contacts, lack of network	Check the location of the gold contacts (should be at the bottom)
Use of an adapter for micro-SIM	Poor contact, overheating of the module	Cut the SIM card to nano format or replace it
Use of force in insertion of tray	Contorted guides, jammed mechanism	Insert the tray smoothly, without distortion
Installation of a SIM card with the phone on	Communication module failure, network errors	Always turn off your smartphone before manipulation.
Getting moisture into the slot	Short circuit, corrosion of contacts	Avoid using your phone in the rain or in the bathroom.

If you've already made one of these mistakes, don't panic. Most of the time, the problem is solved.

🔄 Rebooting the phone.
🧹 Cleaning contacts of SIM card and tray (alcohol) + cotton-stick).
🔧 Resetting network settings (Settings) → System system → Resetting settings).

⚠️ Warning: If the smartphone stopped turning on after a failed SIM card installation or if it gives an error "Baseband is unknown", this is a sign of modem damage. Do not try to disassemble the phone yourself - in the Mi 8 Pro, the communication module is soldered to the motherboard, and its replacement requires soldering equipment.

FAQ: Answers to popular questions

Can I insert a microSD and two? SIM-mapping?

No, the Xiaomi Mi 8 Pro has a hybrid slot: either two nano-SIMs or one nano-SIM + microSD (up to 256 GB).

What if the tray is jammed and it does not come out?

1. Try to remove the tray with a thicker object (for example, an unbended stationery clip). 2. If it does not help, gently tuck the tray with a plastic card (not metal, so as not to scratch the case). 3. In extreme cases, contact the service center - do not apply excessive force, so as not to break the mechanism.

Does the Mi 8 Pro eSIM support?

No, the Mi 8 Pro does not have a virtual SIM (eSIM) module. You can only use physical nano-SIMs.

How to find out which SIM card is active for the Internet?

Go to Settings. → SIM-maps and mobile networks → Mobile Internet. Here will be marked SIM card used for data transfer (icon) 4G/LTE near-room).

Can I use a SIM card from another operator in roaming?

Yes, but set network priority manually. In roaming, the Mi 8 Pro automatically connects to available networks, however, some operators require manual selection (e.g. Settings → Mobile Network → Network Operators → Manual selection).