Why is my micro SD card write protected all of a sudden?

It can be frustrating when you go to save files to your micro SD card only to get an error message that the card is write protected. There are a few potential reasons why your micro SD card may suddenly become write protected.

Quick Summary

Here are some quick potential reasons why your micro SD card may suddenly become write protected:

  • The lock switch on the SD card is slid to the ‘lock’ position
  • The SD card is corrupted
  • There is a problem with the device reading the SD card
  • The SD card is a fake or counterfeit card
  • The SD card is simply worn out and needs to be replaced

The most common reason is that the physical lock switch on the SD card itself has been slid into the ‘lock’ position. This manually sets the card to be read-only. Simply sliding the switch back will unlock the card. If that does not fix the issue, then the problem may be corruption, compatibility issues, or a worn out card.

What Does “Write Protected” Mean?

When you insert an SD card into your device, the device needs to be able to both read data from the card and write new data to it when you save files. However, some SD cards have a “read-only” mode that prevents writing any data to the card.

This read-only state is what is referred to as “write protected.” It means the card cannot be modified with new data until the write protection is disabled. The card can still be read from to access existing files, but no changes can be made to the card.

Common Reasons a Card May Become Write Protected

Here are some of the most common reasons why your micro SD card may suddenly become write protected and prevent saving files:

1. Lock Switch Is Enabled

SD cards have a small physical switch on the side that can toggle between locked and unlocked. If this switch gets moved to the locked position, it will instantly make the entire card read-only.

To check this, take the micro SD card out of your device and inspect the sides and edges for a very small sliding switch. You may need to use a magnifying glass. If you find the switch, slide it back to the unlocked position and try using the card again.

2. The Card Has Become Corrupted

SD cards can sometimes become corrupted, which can lead to read-only errors. This corruption may be caused by:

  • Improperly ejecting the card from the device
  • A bad sector on the card
  • Removing the card while files were still being written
  • Using the card in multiple incompatible devices
  • A faulty card reader or device
  • A sudden power outage

Reformatting the SD card may clear up a corruption issue. However, corruption can often be difficult to repair, and you may need a new card.

3. Compatibility Issue With the Device

In rare cases, your device may report that the SD card is write protected due to incompatibility issues between the device and card.

For example, a very old device may not properly support a brand new SD card with a high capacity or speed rating. Or there may be conflicts with how the device and card communicate based on the controller chips they use.

Trying the card in a different device can determine if compatibility issues are at fault. You may also be able to update the device firmware or drivers to add better support for new cards.

4. The Card Is Fake or Counterfeit

Unfortunately, there is a market for fake and counterfeit SD cards that are designed to trick you into thinking it is a real, high capacity card from a reputable brand. However, these cards often have issues like becoming read-only quickly.

Carefully inspect the card and packaging to look for any signs of being counterfeit. Be especially cautious when purchasing cards online or from risky sellers. Authentic cards will typically work flawlessly and last a long time.

5. The Card Is Worn Out

SD cards have a limited lifespan and can only be written to a finite number of times. If you’ve been using the same card for a very long time, it may simply have reached the end of its usable life.

For cards you use frequently, plan on replacing them every couple of years to avoid failures. Also, look for cards with higher write endurance ratings if you plan to use them extensively.

Other Possible Causes

While less common, here are a few other potential reasons your micro SD card may have become write protected:

  • You accidentally set a read-only attribute on the card’s files in your operating system
  • There is physical damage to the card preventing writing
  • You set a read-only mode using disk utility software
  • A manufacturer set the card to be read-only by default
  • Issues with the SD card standards body preventing writes

Carefully inspect the card and test it in multiple applications or devices to troubleshoot rare issues like these.

Removing Write Protection

If you can identify what is causing your micro SD card to be write protected, here are tips for removing the protection:

  • Unlock the lock switch – Slide it fully over to the unlocked position.
  • Reformat the card – This can fix software corruption issues.
  • Update device firmware – May improve compatibility with newer cards.
  • Replace worn out cards – Cards will fail after extensive long term usage.
  • Avoid fake cards – Only buy reputable brands from trustworthy retailers.
  • Remove read-only attributes – Change permissions if accidentally set.
  • Try a different device – Determines if the issue is device-specific.

If you continue having write protection issues after troubleshooting, the SD card is likely damaged or worn out and needs replacing.

Recovering Data From a Write Protected Card

If your SD card suddenly became write protected, you may be worried about recovering your files and data that were on the card before the issue occurred.

Thankfully, even if a card becomes write protected or corrupted, the existing data is usually still intact and readable. Simply insert the card into a device, and you should be able to access, copy, and back up the files stored on it before the write protection happened.

Some recovery tips include:

  • Use card recovery software to scan and extract data
  • Access the card on a different device if the original is damaged
  • Attach the SD card to a computer to directly browse files
  • Remain patient and avoid forcing faulty cards to work

As long as you don’t continue writing to the card after corruption, your stored photos, videos, music, and other data should remain accessible for recovery.

Preventing Write Protected Cards

To avoid SD card write protection issues in the future:

  • Be gentle and careful when handling the cards
  • Always eject properly before removing cards
  • Watch out for counterfeit cards when buying online
  • Reformat your cards every few months
  • Replace high-use cards annually
  • Check the lock switch before inserting cards

Following best practices for SD card storage and handling will minimize corruptions and extend the usable lifespan of your cards.

When to Replace a Write Protected Card

If you continue having write protection or corruption issues after trying to fix or recover a micro SD card, it may be time to replace it.

Signs it’s time to retire a card include:

  • The card becomes read-only frequently
  • You’ve used the card extensively for over 2 years
  • The card no longer works in devices it used to
  • Reformatting does not solve write protection
  • Data has become corrupted or inaccessible

SD cards are inexpensive and have a limited lifespan, so replacement is cheaper than trying to repair a defective card. Be sure to move your data to a new card or other storage once a card shows signs of failure.

Frequently Asked Questions

Why did my SD card suddenly become write protected?

The most common causes for an SD card suddenly becoming write protected include the lock switch being enabled, corruption, incompatibility issues, counterfeit cards, or simply wearing out from excessive long term use.

How do I unlock a write protected SD card?

First check that the lock switch on the card has not been enabled. Slide the switch back to unlock it. If that does not work, you may need to try reformatting, updating device firmware, or replacing the SD card entirely.

Can a corrupted SD card be fixed?

Attempting to reformat a corrupted SD card can sometimes clear up issues and fix corruption. However, severe corruption often requires replacing the SD card.

Is my data gone if my SD card is write protected?

No, a write protected card will still allow you to read and access existing files. However, you should immediately copy the data to another device or card as corruption can still spread and result in permanent data loss.

How can I recover data from a write protected or corrupted card?

Use data recovery software or access the files directly by attaching the SD card to a computer. Avoid saving new data to the card, and instead copy the retrievable data off the card to another storage medium.


SD card write protection errors can happen suddenly but are usually fixable. The most common causes include the lock switch, corruption, compatibility issues, fake cards, and worn-out cards. Confirm the lock switch position first. Then try reformatting, switching devices, replacing defective cards, and updating firmware as needed. Be sure to recover existing data off the card before it is lost to spreading corruption.

With proper handling and replacement of aged cards, you can minimize and recover from SD card write protection issues.