Many owners of Xiaomi smartphones are faced with a paradoxical at first glance problem: the device reports a lack of space for the smartphone. SIM-But today's tariffs only require a minimal amount of data to be stored, and in the era of cloud syncs and instant messengers, we've forgotten that the physical chip inside the slot has its own, if tiny, storage capacity. This space is usually reserved for a phone book and old text messages that may have accumulated over the years of using the number.
When the storage is overflowing, it can lead to the inability to add a new contact directly to the card or receive an incoming SMS from the bank. The MIUI system installed on Xiaomi devices sometimes incorrectly displays the status of this drive, creating a false sense of overflow. However, you should not ignore such notifications, as this can signal real problems with writing data or damage to the file system of the communication module itself.
In this guide, we will look at where to look for information about a busy place in the Android interface, how to safely clean up redundant records and what to do if standard methods do not help restore the health of the SIM card. You will learn to distinguish between software glitch shell and physical wear of the chip, and also learn what data is really worth keeping on the SIM and which is better to transfer to a Google account.
Where to find information about storage occupancy
Searching for free space information depends on the operating system version and modification of the MIUI or HyperOS shell. In most cases, the standard interface does not display the exact value in kilobytes on the main screen, but provides indirect signs of overflow. To access the management of the SIM card data, you need to go to the device settings menu.
Open the Settings app and find the About Phone section, which often shows basic information, but for a detailed analysis, you need to dig deeper. Go to Status or General Information, where network settings are listed. If the SIM card is full of contacts, the system can show a warning in this section, although the exact amount of free memory in megabytes is rarely seen here.
A more efficient way is to use the contact management menu. Go to the standard Contacts app, click on the three dots or menu button in the corner of the screen, and select Settings. The Import and Export Contacts section often shows the number of occupied and vacant memory cells on the physical chip, which is the most accurate indicator of how much space is left for new records.
⚠️ Note: Do not try to find information about memory SIM-The cards in the Storage section, where you see gigabytes of internal memory on the phone, are two different drives, and the system logically separates them.
Checking through the engineering menu and codes
To get a deeper diagnosis of the status of the communication module on Xiaomi, you can use the hidden engineering menu. This interface is designed for technicians, but provides access to technical information that is not available in normal mode. To log in, open the Phone application and enter a special code.
Dial the combination ##4636##. If the code is active on your firmware version, the Testing menu will open. Select Phone information. Here you can see the network status and, but file system data. SIM-map (FS) However, if the map is damaged or not read correctly, this menu may show login errors or strange signal strength values.
There are other codes specific to MediaTek or Qualcomm processors that are sometimes found in Xiaomi, such as ##3646633##, which can open a full engineering menu. Connectivity or Telephony sometimes has map status information. Be careful: changing the settings in this menu can cause network resets.
What do I do if the codes don't work?
If the engineering menu doesn't show the exact amount of free memory in bytes, don't worry. The main purpose of checking is to see if the entries limit is exhausted. Modern SIM cards have a storage capacity of 32 to 128 KB, which is extremely small by modern standards, but enough for hundreds of contacts, if you do not store extra fields.
Clearing contacts and phone book
The most common reason for lack of space SIM-Old SIMs support a limited number of characters in the contact name and often don't have email fields or addresses. When you try to keep in touch with a long name or additional data on the SIM card, the system emits an error.
To solve the problem, you need to transfer contacts to internal memory or the cloud. Open the Contacts app, go to settings and select Import / Export. SIM-Select save to your Google account or device memory, and after successful copying, you can safely delete all entries from your SIM card by selecting Delete from the device. SIM-map.
- 📱 Open the Contacts app on the home screen.
- ⚙️ Click on the menu (three dots) and select Settings».
- 📥 Select “Import/Export Contacts» -> «Exports with SIM-map».
- 💾 Save a copy in your phone or Google account memory.
- 🗑️ Return to the menu and select “Delete from” SIM-maps to make room.
After cleaning, it is recommended to restart the Xiaomi smartphone, which will allow the system to re-index the phone book and correctly display the status of free space. If after deleting all contacts, a message about a memory shortage remains, it may be the damaged sectors of the chip’s memory.
☑️ Checklist for safe cleaning
Delete old SMS messages
Unlike modern smartphones, where SMS stored in internal memory, some old models or specific settings can store messages directly to the SIM-Although the container for SMS It is minimal (usually until the 20-30 short messages, overflowing this buffer may block new notifications.
To check and clear this section, go to the Messages app. Click on the menu icon or three dots in the corner, then select Settings. Find the Text Messages section (SMS) or SIM-If you have the option to view messages stored on the map, delete old and unnecessary chains of correspondence.
Users often forget about service messages from operators who occupy precious cells. SMS cleaning is a quick way to make room without risking losing important phone numbers. If the message menu does not give access to the SIM card storage separately, try temporarily removing the card and pasting it into a simple button phone: there SIM memory management is implemented more transparently.
⚠️ Attention: Before mass removal SMS Make sure that there are no confirmation codes from banks or important services that you may need to restore access in the future.
Table: Data types and their impact on SIM memory
Understanding what exactly takes up space helps you manage storage more efficiently, and here is a table showing what data is stored on the chip and how it affects the overall volume.
| Type of data | Approximate volume | Impact on work | Recommendation |
|---|---|---|---|
| Contacts (Name + Number) | ~200-500 bytes per record | High (main consumer) | Store it on Google/iCloud |
| SMS text message | ~140 bytes per message | Medium (blocks new SMS) | Remove the old ones at once |
| Network settings (SPN) | Fixed volume | Low (systemic) | Don't touch it. |
| Latest numbers dialed | Minimum | Low. | Clean periodically |
As you can see from the table, the main burden is on contacts. Modern SIM cards like USIM have a slightly larger volume, but the principle remains the same: it is not a full-fledged disk, but a specialized security chip. It is critical to understand that the SIM card is not designed to store files, photos or applications.
Programming errors and resetting network settings
Sometimes the memory problem is false and caused by a software failure in the MIUI shell. The system may mistakenly assume the storage is complete due to cache or process conflict. In such cases, physical cleaning may not help, software reset is required.
Try resetting your network settings. Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. Click Reset. This action will not delete your personal files or contacts, but return network settings to factory values, which often eliminates SIM read errors.
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If after resetting the network settings the error persists, try inserting SIM-If the memory is displayed normally, the problem is with your Xiaomi software. If the error is repeated, the card is physically worn out.
Also worth checking for system updates. Xiaomi regularly releases bug fixes in the telecom module. Go to Settings → About phone and click on the MIUI version to check for updates. The current firmware may contain patches to correctly display memory status.
Physical wear and replacement of the SIM card
SIM cards have a limited rewrite cycle, and if you have used one number and one plastic card for more than 5-7 years, its memory may have deteriorated, and memory cells lose the ability to store data reliably, which is perceived by the system as “space shortage” or damage.
Visually inspect the chip. If there are deep scratches, darkening or chipping on the golden contacts, the card needs to be replaced. Even if it is visually intact, the internal structure may have broken. Communication operators change the SIM cards for free or for a nominal fee, saving your number and tariff.
- 🛑 Frequent network losses or messages “No service».
- 💾 Errors of recording new contacts even after cleaning.
- 📉 Slow number determination work when incoming call.
- ⚡ Heating the area around the SIM card slot (rarely, but possible).
Replacing a new SIM card (especially a Nano-SIM with 4G/5G support) will solve the problem of space shortage once and for all. New cards have a larger volume and more reliable memory structure.
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The most effective solution to the problem of overcrowded SIM memory is to transfer contacts to the cloud and replace the old plastic card with a new one from the operator.