What to Do When Your SIM Card Is Locked Both Ways? How to Unlock

Having your phone SIM card locked both ways can cause concern as you can't make calls and fear your SIM might be confiscated. In this article, Software Tips shares with you the simplest way to unlock a two-way locked SIM right at home!

I. What Does It Mean When Your SIM Card Is Locked Both Ways?

A SIM card being locked both ways means the service provider has blocked all usage capabilities of the SIM (including receiving calls, making calls, sending messages). This means your phone SIM card now cannot make or receive calls or messages but still shows signal on your phone as usual. Calls and messages to your connected SIM will always display the message 'The subscriber cannot be reached at the moment, please call back later.'

When you see your phone showing network signal bars, but you can't make or receive calls, or send messages, that's when your SIM card is locked both ways.

II. Why Is Your SIM Card Locked Both Ways?

In the tightening of telecommunications policies, SIM cards today are often locked both ways. State policies are being combined with network providers to eradicate fake SIM cards, virtual SIMs, and suspicious phone numbers, leading to the blocking of SIM cards in certain cases. Additionally, there are various reasons for a SIM card being locked both ways, including:

• Not Registered Under the Right Name: According to the latest regulations, SIM users must provide accurate information and register the SIM under their own name. Registering the SIM under the correct name helps reduce the use of fake SIM cards in Vietnam. If you haven't registered the SIM under the right name, it will be locked both ways and cannot be used.
• Expired Usage: Some mobile SIM cards have an expiration date, and when it passes, they are locked one way with a warning. However, if you don't unlock it within a certain period, the network provider will consider it abandoned and proceed to lock the other way.
• Unpaid Service Fees: Most users in Vietnam opt for prepaid services, but some use postpaid services. With postpaid services, fees are paid at the end of the month. If you fail to pay according to the service contract, the network provider will lock your SIM card both ways.

• Incorrect PUK Code: Mobile SIM cards have a security feature that requires you to enter the correct code when using the SIM on a new phone. If you enter the wrong PUK code more than 5 times, the SIM will automatically lock both ways to protect the owner.
• Incorrectly Recharging Prepaid Cards More Than 5 Times: If you recharge a prepaid card incorrectly more than 5 times, the network provider will lock the SIM both ways due to suspicion of fraudulent activity. The network sees this as an attempt to exploit recharge card codes, and locking the SIM both ways is a direct preventive measure.
• Reported as Spam: Nowadays, incoming calls from unknown numbers often get flagged as potential spam. If multiple reports label your calls as spam, the network provider will lock your SIM both ways according to state regulations.

III. How to Check If Your SIM Is Locked Both Ways?

Many people worry about their SIM being locked both ways and want to know how to check if it's really locked both ways or not. To check if your SIM is locked both ways, simply follow these steps:

Method 1: Check SIM Lock Status Using *101#

The *101# command is the most common and useful code for checking subscriber information today. This code not only allows you to check your balance but also informs you about the status of your SIM card. If your SIM is locked, the system will display the following:

• The subscriber has been locked one-way.
• The subscriber has been locked both ways.

Method 2: Check SIM Lock Status via Customer Service Hotline

The customer service hotlines of network providers are the ones with the ability to check, access, and modify information on your SIM card. Call the hotline and request the customer service representative to check if your SIM is locked!

• Viettel Network Hotline: 1800 8098 or 198
• Vinaphone Network Hotline: 1800 1091 or 18001 166
• Mobifone Network Hotline: 9090 or 1800 1090
• Vietnamobile Network Hotline: 0922 789 789 or 0923 452 121
• Gmobile Network Hotline: 199 or 01998 880 199
• I-Telecom Network Hotline: 077 798 666 – 037 940 713
• Reddi Network Hotline: 1800 556 883

Method 3: Check SIM Lock Status on Mobile Apps

Today, network providers offer mobile apps on smartphones for users to check SIM status and access accompanying services quickly.

• Download My Viettel app: iOS | Android
• Download Mobifone app: iOS | Android
• Download Vinaphone app: iOS | Android
• Download Vietnamobile app: iOS | Android
• Download Gmobile app: iOS | Android

IV. Guide to Unlocking a SIM Locked in Both Directions

Depending on the specific issue encountered, we will have different methods to quickly unlock a SIM locked in both directions. Below are the simplest and most effective ways to unlock a SIM locked in both directions.

1. Unlocking a SIM Due to Not Being Registered Under the Correct Name

In case the SIM is not registered under the correct name, you need to make sure to check whether the subscriber information is accurate.

Step 1: Check Subscriber Information

Send TTTB to the number 1414 and read the verification message.

If the returned information does not match your personal details, you need to register the SIM under your correct name. If the information is correct, you can skip this step.

Step 2: Register Under Correct Name

Download the corresponding network provider's app to your phone and log in. Select the Subscriber Information Registration section and fill in the required details in the form.

Alternatively, you can call the network provider's hotline and request assistance with registering the subscriber information under the correct name.

2. Unlocking SIM Due to Expiry or Late Payment

For cases where the SIM is locked due to expiry or late payment, unlocking it is now simpler than ever. Simply top up your account to extend the expiry date or make the necessary payment as per the network provider's instructions, and your SIM will be unlocked immediately.

3. Unlocking SIM Due to Incorrect Card or PUK Entry

If you enter the wrong card or PUK code multiple times, you must call the network provider's hotline to request assistance in unlocking the SIM card. Nowadays, network providers only require users to provide basic information: ID number, Name, Date of birth….

4. Guide to Unlocking SIM Locked in All Cases

If your phone's SIM card is locked and you're unsure why, don't worry, you can still unlock it quickly. In any case, the network provider's hotline will assist you in unlocking the SIM card. If you find your SIM card locked, call the network provider immediately for assistance in unlocking it and restoring its functions.

In this article, Software Tricks shares the fastest and most detailed way to unlock a two-way locked SIM. Have a wonderful day!