Previously, a mobile phone could only have a maximum of two SIM cards inserted at the same time, and you could only replace one of them if you wanted to switch. Lucky SIM breaks through this limitation and successfully developed a new technology exclusive to Hong Kong in 2024 – the "eMaster SIM" card. After inserting this card, it can support up to 10 eSIMs and switch between them at any time, while also solving the problem of some mobile phones not supporting eSIMs.

1. 10-in-1 Enhances Phone Functionality
   
   - Up to 10 eSIMs can be written, but only one eSIM will be active at a time. The app can switch to other eSIMs at any time.
   
   
2. Supports specified eSIMs
   
   - Supports "LuckySIM" local/roaming data SIM cards with Hong Kong numbers, prepaid/monthly number portability SIM cards, "Lucky2" data SIM cards, and travel cards.
   
   - Supports most third-party telecom provider eSIMs
   (Updated October 2025. Developed according to the GSMA eSIM standard, regardless of which mobile carrier you use, as long as the eSIM brand meets the relevant standards, it can theoretically be added to eMaster SIM for unified management unless there are special reasons, truly enabling one physical card to control multiple eSIMs simultaneously! However, it is not guaranteed that all brands of eSIMs will be supported by eMasterSIM.)
   
   Whether you're in Hong Kong or traveling abroad in the future, you won't need to worry about changing your SIM card; we offer a more flexible solution.
   
   
3. How to use Android and iPhone
   
   While the eMaster SIM card is usable on both Android and iPhone, the "Lucky eMaster" eSIM management app currently only supports Android devices. If your phone has two SIM card slots, remember to insert the eMaster SIM into the first slot (SIM1 / Slot 1).
   
   - Android devices: Insert the first SIM card into the first slot (SIM1 / Slot 1), manage 10 eSIMs through the "Lucky eMaster" App, and default to one number being active.
   
   - iPhone: Since there is no iPhone app, first insert the eMaster SIM card into SIM slot 1 of the Android phone, then pre-enable one of the numbers in the Android app before inserting it into SIM slot 1 of the iPhone.
   
   
4. Addressing two major pain points of traditional eSIM products
   
   Most mobile phones from mainland China and Hong Kong do not support eSIM.
   Traditional large-scale eSIM services are expensive.

Frequently Asked Questions

Q: What is an "eMaster SIM" card?

A: The "eMaster SIM" is a brand-new SIM card from LuckySIM, offering more powerful features than traditional SIM cards. Its built-in functionality can handle "LuckySIM," "Lucky2," and eSIMs from some telecom operators. Simply insert it into an Android phone or device and use this application to enhance your phone's capabilities: supporting up to 10 eSIMs.
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Q: Which mobile phone models are compatible with the "eMaster SIM" card?

A: Simply put, the "eMaster SIM" card was designed to address the issue of some Android phones not supporting eSIM.

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Q: Which types of devices might not need an "eMaster SIM" card?

A: If your Android phone or iPhone already supports eSIM (most overseas models support eSIM in recent years) , you can simply purchase an eSIM product and then activate it in your phone settings via the QR code in the email. It is not necessary to use an "eMaster SIM" card.

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Q: What is eSIM?

A: eSIM is a virtual SIM card technology built into a device. Unlike traditional physical SIM cards, it does not require actual insertion or replacement of the card slot. eSIM can be configured and activated via software, allowing users to easily switch mobile network operators or data plans.

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Q: How can I tell if my phone supports eSIM?

A: The list of commonly used mobile devices that support eSIM is not exhaustive. If you have any questions, please contact the relevant device brand. The following two methods are for reference only.

• 【Method 1】Check if there is an option to add an eSIM in your phone. Go to "Settings" > "Mobile Service" and check if there is a path to "Add eSIM".
• 【Method 2】Please dial "*#06#" to see if EID is displayed on the screen. If EID is displayed, it means that the phone can use eSIM.

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Q: How do I install my newly purchased eSIM?

A: You can click "Add eSIM" on the main screen and then install your newly purchased eSIM using the following two methods:

- Scan the QR code
- By manually entering the activation code.

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Q: How many eSIMs can I install on my "eMaster SIM"?

A: You can install up to 10 eSIMs into the "eMaster SIM".
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Q: How do I purchase an eSIM?

A: 1Worldsim.com is the first to offer the latest Lucky SIM eSIM! This includes LuckySIM with a free Hong Kong number for Hong Kong/roaming data, and Lucky2 data/travel SIM card.

You must ensure your phone/mobile device supports eSIM. You will receive an eSIM QR code/activation code via email, which will be used for installation and activation. Your email and SMS contact number must be correct, as the system cannot change or resend them.

Prices and details for over 50 products, with the latest offers continuously updated. You can order through the following links:

• 【1】Order Form: https://forms.gle/gcNW5kc4zqMbw9q8A
  PayMe / Bank Transfer / Faster Payment System / Alipay

• [2] New online store: https://1worldsim.com/
  Credit card (price including transaction fees)

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Q: How can I check the current data usage?

A: Activate your eSIM and then look up the following common function codes (USSD Codes):

- Local data usage, see "*116*1#"
- For data usage related to overseas travel, please use "*116*2'#".
- For eSIM expiration date, press "*116#".

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Q: What are the features of the "Lucky eMaster" Android App?

A: The Lucky eMaster app is a dedicated application for the eMaster SIM, used to manage LuckySIM, Lucky2, and eSIMs from some telecom operators on your phone. You can install up to 10 eSIMs into your eMaster SIM through this app. By scanning a QR code, the eSIM can be instantly downloaded to your device, and you can switch between installed eSIMs with a single click. Please note that once an eSIM is removed from your device, it cannot be restored.

Google Play download link: https://play.google.com/store/apps/details?id=com.luckysim.luckyemaster

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Q: Which telecom operators' eSIMs can be written to the "eMaster SIM" card?

A: "eMaster S1M" supports various eSIMs under the LuckySIM brand, including "LuckySIM" and "Lucky2". While it technically supports eSIMs from other telecom operators, successful data writing cannot be fully guaranteed, especially for numbers that require real-name registration .

"eMaster SIM" is developed based on the GSMA eSIM standard. Regardless of which mobile carrier you use, as long as the eSIM brand meets the relevant standards, it can theoretically be added to eMaster SIM for unified management, unless there are special reasons. This truly allows one physical card to control multiple eSIMs simultaneously! However, it is not guaranteed that all brands of eSIMs will be supported by eMasterSIM.

Startup steps

The following method uses eMaster SIM. Please ensure your phone supports the Android system first.

【Step 1】Open the packaging and take out the eMaster SIM.