Replacement SIM-Xiaomi Redmi cards to send SMS: full-length instruction

Why do we change? SIM-Xiaomi Redmi card and what you need to know before you start

Replacement SIM-Xiaomi Redmi cards are a procedure that every user will face sooner or later. switching to a new operator, replacing a damaged card, activating an additional number, or even a banal desire to use a more modern nano-SIM format instead of an outdated micro-SIM. SMS, There are some nuances here.

The fact is that Redmi (especially in dual-slot models) sometimes has problems with determining the primary number for messages. SIM Smartphones can send by default SMS You can't just go to another number or ignore the new card altogether, and you can't get the right job. SMS firmware MIUI manual adjustment is required APN — Even if the internet is working without problems.

In this article, we will not only discuss the mechanical part (how to physically remove and paste a card), but also the software subtleties: from choosing a slot for SMS to solving typical errors like “failed to send a message.” And you will learn why some Redmi Note 10 and later models can get lost when replacing the SIM, and how to avoid this.

What tools will be needed to replace SIM-map

At first glance, it seems to be a replacement. SIM-You only need a paper clip or a key, but in practice, you better prepare yourself in advance so you don't run into the unexpected:

• 🔑 Key to extracting tray SIM (If you're missing, you'll get a straight clip or a thin needle.
• 📱 New SIM-Nano-SIM card (99% of modern Redmi cards only support it) If you have a micro-SIM or mini-SIM, it should be trimmed or replaced in the cabin of the operator.
• 📎 Tweezers or plastic spatula (in case the card gets stuck in the tray).
• 🔋 Charger – If the battery is under 20%, some Redmi models may not turn on after rebooting.
• 📡 Wi-Fi or other phone access – to check the network after replacement.

Pay special attention to the format SIM-For example, Redmi Note 11 and later support only nano-SIM, and in Redmi 9A You can also find a combined tray under microSD. + If you try to insert micro-SIM into a slot for nano, it can damage the contacts!

Step-by-step: how to remove the old SIM-map

Extraction process SIM-The cards on all Redmi are almost the same, but there are differences in the slot location. For example, in the Redmi Note 10 Pro, the tray is on the right, and in the Redmi, the tray is on the right. 9T — General scheme of action on the left:

1. Turn off your smartphone (optional, but recommended for safety).
2. Find a tray for SIM-cards - usually marked with a small hole.
3. Put the key (or paperclip) in the hole and press until the tray is pushed out.
4. Carefully remove the tray and remove the old one SIM-map.

If the tray is not extended:

• 🔧 Check if the key is bent – it must enter strictly perpendicular.
• 💡 Try pressing from another corner or swaying the key slightly.
• ⚠️ Don’t put too much effort into it – if the tray doesn’t lend itself, it may be locked because of a phone drop.

⚠️ Note: Some Redmi models (e.g. Redmi) K40) The tray is fixed by a spring mechanism, and if you pull it out too sharply, the spring can fly out, and the tray will stop holding, and then you need to disassemble the phone.

Installation of a new SIM-Maps: Procedures and Typical Errors

Now we move on to installing a new one. SIM-The key here is to place it in the tray correctly. Most Redmis have a diagram on the tray showing which side to insert the card:

• 🔸 The cut (mown angle) should be directed in the direction opposite to the contacts.
• 🔸 The golden contacts should be facing downwards (to the inside of the phone).

After installation of the map:

1. Carefully insert the tray back before the click.
2. Turn on the phone (if it was turned off).
3. Wait for the network signal to appear (it can take up to 2 minutes).

Typical errors in installation:

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If, after the replacement, SIM phone does not see the network, try to manually select the operator in the settings: → SIM-maps and mobile networks → Network selection. Sometimes automatic search loops.

Setting up SIM-dispatcher SMS Xiaomi Redmi

Even if it's new SIM-The map is defined and there is a network, this does not guarantee that SMS Redmi with two slots often has a lot of confusion about which number to send messages from:

1. Go to Settings. → SIM-maps and mobile networks.
2. Choose. SIM-the card you want to use for SMS.
3. Click on Settings. SIM-map and set it as the main message.
4. If you don’t have an option, check if you have a third-party SMS application (like Google Messages) that ignores your system settings.

On some MIUI firmware (especially on Redmi Note 8/9), the APN (access point) may be knocked down after the SIM is replaced, which causes SMS to be sent and MMS to not.

1. Go to Settings. → SIM-maps and mobile networks → [Yours. SIM] → Access points (APN).
2. Click on the three dots in the top right corner and select Reset to default values.
3. If this does not help, add APN manually (you can take the options on your operator’s website).

⚠️ Note: If you are using Redmi with firmware MIUI Global and after replacement SIM stopped coming SMS From banks or services, check if the built-in spam filter is blocking them. → Settings → Spam filter.

What to do if you replace it after replacement SIM not depart SMS

If you did everything according to the instructions, but SMS still do not send, here is the diagnostic algorithm:

1. Check balance – sometimes operators block sending SMS with zero or negative balance.
2. Make sure that SIM-Card activated – new cards may require activation USSD-command (e.g. *111# for MTS).
3. Check the SMS center: Open the Messages app. Click on three dots → Settings → Settings → SMS center. Make sure the correct number is listed (usually in +79991234567 format).

Reset the network settings:

→ SIM-maps and mobile networks → [Your SIM] → Network reset

If the problem persists, try:

• 📱 Install another application for SMS (For example, Google Messages or Textra).
• 🔄 Restart your phone in Safe Mode (hold the power button) → Safe regime).
• 📡 Temporarily disable Wi-Fi – sometimes a conflict between Wi-Fi and the mobile network interferes with sending SMS.

Features of replacing the SIM on popular models Redmi

While the process of replacing the SIM on most Redmis is similar, some models have their own nuances.

Redmi Note 10 Pro and newer after replacement SIM You may notice that you've reset your Mi Account, and that's okay, because your phone checks if you've been in the past. SIM-The card was stolen. Just confirm it's your account.

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On 5G-enabled models (such as the Redmi Note 11 Pro+ 5G) after the SIM is replaced, it may be necessary to re-activate the 5G network in the mobile network settings.

FAQ: Frequent questions about replacing the SIM with Xiaomi Redmi