How to Transfer Your SIM Card to a Different Phone

A SIM card connects your phone to the GSM network (Global System for Mobile Communications). Once you insert your SIM into an unlocked phone, you'll be able to use your mobile provider's services. Similarly, if your phone is unlocked, you can use SIM cards from various carriers, which is especially handy when traveling. When swapping SIM cards between phones, ensure the new device supports the SIM from your network provider.

Open your contacts app on the phone you’re currently using. You can back up your contacts to your SIM card before making the switch, though this isn’t the most convenient method. This approach is only recommended for basic phones; for smartphones, your contacts are typically synced with your Google or Apple ID account.

Open the menu and select "Export" or a similar option.

Set the SIM card as the destination for the contacts you wish to export.

Check the SIM card size for each phone. SIM cards typically come in three standard sizes, but your phone might require a different size. This is especially true for phones made a few years apart. Some carriers offer free SIM card swaps to match your phone’s size.

• You can use a special SIM cutter to reduce the size of your SIM card, or request a new one with the correct size from your provider.
• If the SIM is smaller than the slot, you can place it in a SIM adapter and use it without issue.

Get a New SIM Card if Switching Carriers. When changing mobile providers, you’ll need to purchase a new SIM card. After registering for service and providing the necessary information to the carrier, you’ll receive a new SIM. If you're switching networks and need a different-sized SIM, contact customer support (this may be free, depending on the carrier's policy).

• Some carriers now use CDMA (Code Division Multiple Access) technology, which doesn’t require a SIM card. However, most 4G networks still require a SIM card. For example, Verizon Wireless in the U.S. uses CDMA for their network but requires a SIM card for 4G LTE access. In Vietnam, CDMA is less commonly used compared to GSM.

Remove the back cover of your old phone. If your phone has a protective case, you’ll need to remove it to access the SIM card.

Locate the SIM card. Depending on the model of your phone, the SIM card could be in different places:

• Check the SIM tray. Many modern smartphones have a SIM tray on the side of the phone. Use a SIM eject tool or a straightened paperclip to poke into the small hole next to the tray to pop it out.
• Check behind the battery. For some phones, the SIM card is placed behind the battery, so you’ll need to remove the battery to reach the SIM.

Remove the SIM card from the phone. After finding the SIM card, carefully take it out.

• If your phone uses a SIM tray, use a SIM eject tool or a paperclip to open the tray. Then, slide it out and remove the SIM card from the tray.
• If the SIM card is behind the battery, you can slide or press the SIM to release it, depending on the design of your phone.

Insert the SIM card into the new phone. To do so, simply reverse the steps you followed to remove the SIM card from the old phone.

Begin the activation process for your new phone (if applicable). If you’re setting up a brand-new smartphone, you’ll need to go through the initial setup steps. During this process, the SIM card is typically activated automatically on the new phone.

• Learn how to activate an Android phone by following the guide for Android setup.
• Read the article Activating iPhone for instructions on how to activate an iPhone during the initial setup process.

Insert the SIM card and power on the phone. After powering up your phone, especially if you've just swapped SIM cards, you may need to wait a few moments for the service to be activated. Simply insert the SIM card, turn on the phone if it’s off, and wait for the connection to be established. You’ll see signal bars (usually with the carrier’s name) in the notification area of the screen once activated.

Contact the service provider if you can’t connect. If your SIM card still doesn’t work on the new phone, you’ll need to get in touch with your carrier. Since your phone is unable to connect, you may have to borrow someone else’s phone to call the carrier’s support line or take your new phone to a carrier service center for activation assistance.