The sudden appearance of a notification that SIM card is fulloften takes users by surprise, blocking the ability to receive new messages. This is a common problem in the operating system Android, which occurs due to the limited amount of built-in memory of the subscriber identification module. Unlike cloud services, a physical chip card has strict limits on the amount of stored data, and ignoring this warning can lead to the loss of important information from banks or delivery services.
The main reason lies in the overflow of the incoming buffer SMS messages, which by default is saved exactly on chip, not in the phone's memory. Modern smartphones often automatically transfer correspondence to internal storage, but older models or specific settings can save everything to SIM. To restore normal operation of the device and not miss confirmation codes, you need to manually free up space or change storage settings.
In this article we will analyze in detail the algorithm for clearing the SIM card memory, look at the hidden functions of the message menu and explain how to forget about this error forever. You will learn how to transfer data without loss and which applications may conflict with the standard communication module. Following these simple steps will only take a few minutes, but will give you full control over your incoming communications.
Causes of SIM card memory full
SIM card memory is a tiny piece of non-volatile memory built into a plastic base. Its (volume) was initially designed to store a small number of telephone numbers and dozens of text messages in the format GSM 03.40. When users receive many messages from services, banks and notification services, this limit is quickly exhausted, since modern services often send long texts that occupy several memory cells.
The second reason is the lack of automatic synchronization with the cloud or the internal memory of the smartphone. Many users do not delete old SMS for years, considering them unimportant, but for the system, each entry is a busy byte. If the settings of the Messages application set storage priority to SIM, then even after clearing the phone's memory, the error will not go away.
⚠️ Attention: Do not confuse the full SIM card memory and the full internal memory of the smartphone. These are different errors that require different solutions. Make sure that the notification specifically concerns the communication module.
It is also worth considering the technical wear and tear of the chip. Old SIM cards, released more than 10 years ago, may have less available memory compared to modern ones. In such cases, even a standard number of messages can cause a failure, requiring more frequent cleaning or replacing the card with a new one from the operator. USIM. In such cases, even a standard number of messages can cause a failure, requiring more frequent cleaning or replacing the card with a new one from the operator.
Diagnostics: how to check the fullness
Before taking radical measures, it is necessary to accurately determine the storage fullness status. In the standard interface Android this information is often hidden deep in the menu. To begin, open your default messaging app. Click on the three dots in the corner of the screen or the "More" button to open the context menu.
In the list that opens, select "Settings". Next, look for a section that may be called “Text messages (SMS)”, “SIM Settings” or “SIM Card Management”. This is where technical statistics are displayed. If you see the message "SIM memory: 45/50", this means that there are only 10 slots free, and the system is about to block the reception of new correspondence.
In some shells, for example, in MIUI from Xiaomi or OneUI from Samsung, the path may differ. Here you should use the search in your phone settings. Enter the word “SIM” or “Messages” into the search bar, and the system itself will tell you where the memory status is located. This is especially useful if the menu is not completely translated or the items are hidden.
Hidden codes for diagnostics
Some phone models allow status through the engineering menu by entering the code ##4636## in the dialer. However, this method does not work on all devices and requires caution, since changing parameters in the engineering menu may disrupt the operation of the radio module.
Instructions: clearing the SIM card memory
The most effective way to solve the problem is to manually delete unnecessary messages directly from the chip. This process requires care to ensure you don't accidentally erase important verification codes or passwords. Open the Messages app and find your Inbox. If you have an old phone, messages can be divided into “Inbox on SIM” and “Inbox on phone.”
Select messages that are not valuable: advertising mailings, old codes from sites, balance notifications. Click on them and hold your finger until the selection check mark appears. After selecting a group of unnecessary entries, click on the trash can icon or the "Delete" button. The system will ask for confirmation - agree.
☑️ SIM cleaning algorithm
If standard deletion does not help or the button is inactive, try moving messages. In the message management menu, select the "Copy to phone" or "Move" option. After all the important data is in the internal memory of the smartphone, you can safely clear the SIM card itself completely using the “Delete all SIM messages” function.
| Action | Result | Risk of data loss |
|---|---|---|
| Deleting one by one | Releasing 1 slot | Low |
| Removing everyone from SIM | Full clearing | High (no reserve) |
| Moving to phone | Save + clear SIM | Minimal |
| Format SIM | Reset all settings | Critical |
Setting message storage on Android
To prevent the “SIM card is full” problem from returning, you need to change the priority storage location. In modern versions Android this is done in the settings of the Google Messages application or the standard application from the manufacturer. Go to settings, select "Advanced" or "Advanced settings".
Find the "Storage" or "Save to" option. Make sure that "Phone" or "Internal storage" is selected and not "SIM card". The smartphone's memory amounts to gigabytes, which allows you to store hundreds of thousands of messages without the risk of overflow. Automatic saving to the phone is a key parameter for comfortable use.
Use backup applications such as SMS Backup & Restore to automatically send copies of all SMS to Google Drive. This will protect your correspondence even if you lose your phone.
It is also recommended to enable the auto-delete function for old messages. Some smartphones have a “Delete old messages” setting, which automatically deletes the oldest correspondence when the number of messages exceeds a set limit (for example, 1000 pieces). This creates the effect of “infinite” storage.
Transferring contacts and messages to a new phone
Users often encounter an overflow error when trying to transfer data to a new device. When importing contacts from an old SIM card to a new Androidsmartphone, the system may try to copy the messages associated with them, which causes a crash. It is better to use cloud synchronization through your account Google.
To transfer contacts, open the Contacts application, select Manage Contacts and click Import/Export Contacts. Select the source "SIM card" and the destination "Phone" or "Google account". After successful copying, the contacts will be available on any device after logging into your account, and the SIM card can be cleared.
⚠️ Attention: When transferring contacts from a SIM card, names may be trimmed to 15-20 characters due to limitations of the old storage format. Check your contact list after import.
If you are changing the phone completely, use the built-in migration tools, such as Smart Switch for Samsung or the built-in reset and setup when you turn on the new phone for the first time. These tools ignore SIM card limits, transferring data directly between devices via Wi-Fi Direct or cable.
Alternative solutions and SIM replacement
If software methods do not help, the physical wear of the chip may have reached a critical point. Microcracks or degradation of memory cells can lead to false reports of overflow or a real inability to write new data. In this case, the only correct solution is to replace the SIM card with your telecom operator.
The replacement procedure is usually free or costs a symbolic amount. You will be issued a new card with the same number and tariff, but with a modern chip that supports more functions and has more memory for service data. This will also improve the quality of communication in areas of poor reception, as the new chips work better with 4G/LTE networks.
Replacing an old SIM card with a new one (USIM) solves 99% of problems with memory errors and improves connection stability in 4G networks.
It is also worth considering the transition to fully digital solutions if your smartphone supports the technology eSIM. A virtual SIM card does not have physical memory in the traditional sense and uses phone resources, which completely eliminates the possibility of overflowing its own buffer with messages.
Frequently asked questions (FAQ)
Will my correspondence be deleted when replacing the SIM card?
No, replacing the SIM card will not affects messages saved in the phone's internal memory or in the cloud. However, messages stored directly on the old SIM card will be lost unless you first copy them to the phone's memory.
Is it possible to recover messages deleted from a SIM?
Recovering messages deleted directly from the SIM card chip is almost impossible without special expensive equipment. Therefore, before cleaning, always make a backup copy of important codes and notifications.
Why do messages arrive but are not saved?
This is a classic sign of overflow. The phone receives a data packet from the operator, tries to write it to the allocated SIM memory cell, does not find free space and rejects the recording, although technically the message was delivered to the network.
Does SIM fullness affect the quality of calls?
There is no direct effect on voice quality, but you may stop receiving SMS with authorization codes, which indirectly blocks access to banking applications and messengers that require confirmation via SMS.