An eSIM, or embedded-SIM, is a digital SIM card built directly into your device that functions without the need for a physical SIM card. It allows users to download and activate cellular services over the internet, providing a more convenient and flexible experience. This eliminates the need for physical card swaps, making it especially beneficial for international roaming.

Using the Mars eSIM Physical Card instantly upgrades your non-compatible phone with eSIM functionality, so you never have to worry about internet issues while traveling abroad.

The card looks exactly like a standard physical SIM card. Simply insert it into your phone's SIM slot, and your device will gain an extra eSIM space where you can download and manage data plans from various countries at any time.

Please verify your device's compatibility before purchasing. You can check using the following methods:

1. Dial *#06#: Open your phone's dialer and enter *#06#. If an EID number is displayed, your device likely supports eSIM. Please note: This method is for preliminary assessment and does not guarantee 100% compatibility.
2. Check Settings: Before placing an order, go to your phone's settings and look for options such as "Add eSIM," "Add Data Plan," or "Add Cellular Plan." If these options are visible, your device is eSIM-ready.
3. Please ensure that your device is "unlocked." An unlocked phone allows you to use eSIM cards from different carriers. In some cases, even if a phone model supports eSIM, certain countries or regions may impose restrictions that prevent eSIM usage or limit it to specific carriers only.

⚠️ Reminder: Issues such as regional version differences, carrier locks, or incompatible older models must be verified and resolved by the user prior to purchase.

Many phones (especially contract-based devices from abroad) are tied to a specific carrier, known as a "Carrier Lock." If you are unsure if your phone is unlocked, please follow these steps to check:

For iPhone Users

1. Go to Settings > General.
2. Tap About.
3. Scroll down to the "Carrier Lock" section:"No SIM restrictions": Congratulations! Your iPhone is unlocked and ready for Mars eSIM."SIM locked": This means your device is restricted. Please contact your original carrier to request an unlock.

For Android Users

1. Go to Settings > Connections (or "Network & Internet").
2. Select Mobile Networks > tap Network Operators.
3. Turn off "Select automatically" to scan for available networks:Multiple carrier names appear: Your Android phone is unlocked.Only your current carrier appears: Your phone may still be locked.

💡 Pro Tip:
If you confirm your phone supports eSIM but it appears locked, contact your original carrier and mention you need to use the device abroad to request a ·

For iPhone Users: Before activating your eSIM, go to Settings > Cellular. Scroll to the bottom and tap "Reset Statistics." You can then monitor your usage under "Current Period" in the "Cellular Data" section.

For Android Users: You can typically view your daily or total data usage under the "Network & Internet" or "Data Usage" section within your phone's Settings.

• Disable Auto-Updates: Turn off automatic updates for apps you don’t need immediately.

• Background Syncing: Temporarily disable cloud syncing and backups for apps like Google Photos, iCloud, and Email.

• Video Auto-Play: Turn off the auto-play feature on social media apps like Facebook and YouTube.

• System Updates: Ensure that automatic OS and App Store updates are disabled.

• Use Public Wi-Fi: Connect to local free Wi-Fi whenever available to conserve your mobile data.• 

• Light Users: For messaging and basic web browsing. 1GB per day is typically sufficient.

• Active Users: For navigation (Google Maps) and uploading photos to social media. We recommend 2GB per day.

• Heavy Users: For video streaming, remote work, or high-volume data needs. We suggest 3GB+ per day or an Unlimited Plan.

When your speed is limited to 128kbps, you can still send and receive text-based emails and messages (such as text on LINE or WhatsApp). However, browsing websites or using social media will be significantly slower, and loading content will require more time.

Network speeds may vary depending on factors such as the density of local base stations, location, terrain, building interference, number of concurrent users, and weather conditions.

⚠️ Important: Please note that telecommunications infrastructure varies by country. Dissatisfaction with network speed due to local infrastructure does not constitute grounds for a refund. ⚠️

The Fair Usage Policy (FUP) is a set of guidelines implemented by local telecommunications carriers to maintain network quality for all users. When an individual consumes an excessive amount of data in a short period—through activities such as streaming high-definition videos, live broadcasting, video calling, or downloading large files—the carrier may temporarily reduce (throttle) their connection speed. This ensures that a single high-bandwidth user does not negatively impact the internet experience of others, allowing everyone to enjoy reasonable connection quality.

Most eSIM plans available on the Mars eSIM Store support 5G connectivity, though some regions are limited to 4G services. Please note that actual internet speeds may vary based on factors such as local carrier coverage, location, terrain, building interference, number of concurrent users, and weather conditions.

Currently, the eSIM plans available on the Mars eSIM Store are data-only and do not include a local phone number. If you need to make calls or send messages, we recommend using communication apps such as LINE, WhatsApp, or Messenger.

Yes, all eSIM plans available on the Mars eSIM Store support hotspot sharing. As long as your device has a personal hotspot feature and the eSIM itself supports sharing, you can connect other devices through your eSIM.

⚠️ Note: Hotspot sharing can consume data very quickly. To ensure the best experience and prevent early data exhaustion, we recommend purchasing a dedicated eSIM for each device. ⚠️

Yes, installing an eSIM only changes your network source; it will not delete or affect the data and settings within your apps.

⚠️ Important Notice: Due to varying telecommunications policies in different countries, we cannot guarantee that all apps will function normally across borders. Please be aware of potential local restrictions. ⚠️

✈️ Before Activating Your eSIM Abroad — Have You Set Up Your Taiwan Number?

 Even if you’re using an eSIM for internet access while traveling, you’ll still need to keep your Taiwan mobile number active to receive verification codes (such as for LINE, banks, or social media logins).

Please make sure to complete the 3 steps below before you travel:

 ✅ Step 1: Enable Voice & SMS Roaming on Your Taiwan SIM

Before you leave Taiwan, contact your mobile carrier to ensure the following features are enabled: 

• ✅ VoLTE roaming
  
• ✅ International calls
  
• ✅ International SMS
  
  

🔔 Note: Many Taiwanese users have international features disabled by default — make sure to check in advance!

 ✅ Step 2: Set Your Taiwan Number as the Default for Calls/SMS

 If you’re using a Taiwan SIM for SMS and a foreign eSIM for data, you must set your Taiwan number as the default for voice/SMS.

Otherwise, you won’t receive verification messages abroad.

📱 How to set it up on different phones:

◉ iPhone

 Settings > Cellular > Default Voice Line > Select your Taiwan number (+886)

◉ Google Pixel

 Settings > Network & Internet > SIMs > SMS Preference > Choose Taiwan number

◉ Samsung Galaxy

 Settings > Connections > SIM Manager > Text Messages > Choose Taiwan number

 ✅ Step 3: Receive Taiwan SMS While Abroad

 Once the settings above are complete, you’ll be able to:

• ✅ Receive Taiwan SMS abroad normally (e.g. OTP, LINE verification, banking messages)
  
• ⚠️ Sending SMS may incur roaming fees — please check with your carrier
  

💡 Tip: Receiving SMS is usually free, but sending may cost extra.

Physically, they look identical and fit into the same SIM slot. The difference lies in their function: a standard SIM card is pre-linked to a specific carrier and data plan, whereas the Mars eSIM Card is a physical bridge that enables eSIM capabilities on your device. It arrives blank, allowing you to install and switch between international eSIM plans via an app. This effectively brings eSIM functionality to Android phones that don't natively support it.

No. The Mars eSIM Card provides the eSIM functionality only and does not include any pre-installed data plans. After receiving the card, you will need to purchase a plan from the Mars eSIM Store or scan an eSIM QR Code provided by another carrier to install it. You will be able to access the internet once the plan is activated.

Yes. Currently, the card only supports Android devices (Android 9.0 or higher) that have access to the Google Play Store to download the Mars eSIM App. You must use our dedicated App to manage your eSIM profiles.

It is not recommended at this time. The core functions of the Mars eSIM—such as downloading and managing eSIM plans—must be performed through our dedicated Android App. Currently, iOS devices do not support this app, making it impossible to install or manage plans on an iPhone or iPad.

Currently, we only support the use of one Mars eSIM Card per device. However, a single card can store between 8 to 10 eSIM profiles. Whether you are traveling for business or leisure, you can enjoy hassle-free internet access by easily switching between your saved plans.

Since the Mars eSIM Card occupies the physical SIM slot, you will need to free it up to use our service. If you wish to keep your original number for calls, we recommend converting your primary number into an eSIM through your current carrier. (Many carriers offer the first conversion for free). Once the slot is empty, you can insert the Mars eSIM Card and enjoy its benefits.

Yes. To ensure the best user experience, please use the Mars eSIM App to manage your plans. We strongly recommend avoiding your phone’s built-in eSIM management tools to prevent potential compatibility issues. You can download the Mars eSIM App for free from the Google Play Store to easily manage multiple eSIM profiles.

• It allows you to scan eSIM QR codes to download, store, enable, disable, and manage your plans directly on your phone.

• You can manage up to 10 eSIM profiles at once.

• Use Mars eSIM plans to enjoy full exclusive features: One-click activation, real-time data tracking, expiry checks, and plan sharing.

• It is perfect for business travelers who need to separate work and private lines, or tourists who want to switch to local, low-cost data plans abroad.

One card can store approximately 10 eSIM profiles (depending on profile file size). However, you can only enable (turn on) one plan at a time for data usage. You can switch between plans in the App within seconds without needing an internet connection.

Yes. Mars eSIM follows international standard specifications. As long as you have a valid eSIM QR code from another carrier, you can use the "Scan" or "Import Image" function in our App to install it onto the card.

Please note that full app functionality—including one-click activation, real-time data tracking, expiry date checks, and sharing plans with friends—is exclusive to plans purchased directly from the Mars eSIM store to ensure a more seamless travel experience.

⚠️ Note: If the eSIM plan from another provider is explicitly labeled as "iPhone Only" or "Does not support Android devices," it cannot be installed or used with Mars eSIM Physical Card.

Yes. The eSIM profiles are stored securely inside the Mars eSIM Physical Card, not the phone. Simply insert the card into another compatible Android phone and download the Mars eSIM App to manage your existing plans.

You can purchase them exclusively at the Mars eSIM Store. We currently do not have physical retail stores.

No. The card is a one-time purchase with no monthly rental or subscription fees. You only pay for the specific data plans you choose to buy.

1. eSIMs purchased from Mars eSIM: eSIMs are one-time-use virtual products. Accidental deletion is considered user error; therefore, it cannot be reinstalled, cancelled, or refunded.
2. eSIMs from other brands: The Mars eSIM App cannot restore or reinstall third-party plans. Please contact the original provider of that eSIM for assistance.

Hardware Issues: If the App says "No card inserted," contact Mars eSIM Customer Service.

Network Issues: If you have a signal but cannot access the internet/slow speeds, and you are using a 3rd party eSIM, please contact that carrier's support. (If the plan was bought from us, contact us directly).

You can complete your purchase directly without registering or logging in. However, becoming a member offers several benefits:

Member Discounts: Accumulate spending to upgrade your membership level and enjoy sitewide discounts for a full year.

Faster Checkout: Your personal information will be saved after your first order, making future checkouts much quicker.

Available Login Methods:

1. Email & Password (Account creation required)
2. Facebook Login
3. Google Login
4. LINE Login

• Credit Card

Pay online using your credit card.
How to pay: Go to your cart → Checkout → Select “Credit Card (One-time Payment)” → Complete the payment without leaving the page to avoid transaction failure.

• Apple Pay

Pay online using Apple Pay.

How to pay: On your iPhone, go to your cart → Checkout → Select “Credit Card (One-time Payment)” → Choose Apple Pay → Tap “Pay with Apple Pay” to complete the transaction.

⚠️ Note: Apple Pay availability depends on your device and browser.
1. On iOS 16 or later, Apple Pay works in any browser.
2. On iOS versions below 16, Apple Pay is only supported in Safari.
3. On macOS, Apple Pay is only supported in Safari.

• Upon completing your order on our official website, you will receive an "Order Confirmed" email from service@marsesim.com. Immediately following this, a second email with the subject "Mars eSIM QR Code" will be sent from no-reply@marsesim.com. Please open that email to retrieve your QR Code.”

⚠️ If you don’t receive the email, please check your spam or all mail folders, and search using our email address or subject line. ⚠️

• Payment failed or error occurred:
If your payment was not completed due to verification timeout or other issues, you won’t be able to retry payment. Please check whether the 24-hour payment window has expired. If it has, simply place a new order.

• Order changes or cancellations:
Once payment is completed, orders cannot be canceled, modified, or refunded.

• How to check your order:
Log in to your member account and visit the Orders page to view your full purchase history.

Mars eSIM is classified as an “international telecommunications service” (e.g., international data cards, roaming cards). According to the Value-Added and Non-Value-Added Business Tax Act of the Republic of China (Taiwan), such cross-border telecommunication services are subject to zero-rated VAT and are not required to issue a uniform invoice. Therefore, we do not provide additional electronic or paper invoices.

A “Purchase Receipt” (not a uniform invoice) will be provided for each eSIM order.
The receipt includes: product names, amounts, payment method, and other related details.

• The receipt reflects the total amount for the entire order; itemized or split receipts are not available.
• If any coupon or discount code was applied, the receipt will show the discounted amount.
• The receipt can be used for internal reimbursement or personal record purposes.

Yes. A uniform invoice will be issued for every purchase of a Mars eSIM Physical Card. To protect your return rights, the e-invoice will be automatically sent to your registered email address after the 7-day inspection period (starting from the day after the product is received).

Zero-rated VAT refers to specific types of transactions that are subject to a 0% VAT rate. According to tax regulations, services that qualify as cross-border telecommunications — such as eSIM international data plans — are used outside of Taiwan, and therefore meet the criteria for zero-rated VAT.

⚠️ Since zero-rated transactions are not required to issue invoices, electronic invoices are also not applicable.

Yes. Please provide the following information in the “Order Notes” section during checkout:
• Company Name
• Business Tax ID (Uniform Number)

No.
eSIMs are one-time-use virtual products. Once the order is placed and the QR code has been issued, the product is considered delivered. Therefore, cancellations, changes, or refunds are not allowed.Please make sure your device supports eSIM before placing your order.

No.
Please make sure your device supports eSIM before purchasing. Refunds cannot be issued if the eSIM cannot be used due to an incompatible device or failure to check compatibility.

Please contact customer support immediately.
Make sure to reach out to us via airport or hotel Wi-Fi as soon as you arrive at your destination — we will assist you right away.

⚠️ Refund requests made after returning from your trip without prior contact will not be accepted. ⚠️

Yes — but it must be verified by customer support.
If our technical team confirms that the issue is due to a service error (not device incompatibility), a refund can be issued.The refund amount will be limited to the actual amount paid. We do not accept claims for additional compensation (e.g., emotional distress, travel delays, etc.).

Yes, but the following conditions must be met:

• The product must be unopened, unused, and in its original packaging.
• You must contact customer support within 7 days of receiving the item to request a return.
• After submitting the return request, you must ship the product back within 7 days.
• Returns will not be accepted if the product is incomplete or the request is submitted after the deadline.
• The maximum amount of any refund shall not exceed the total value of the original order.

Please use a trackable shipping method (such as registered mail or courier service).
If the item is lost due to using a non-trackable method, we will not be able to process your refund.
We recommend keeping your shipping receipt and tracking number for reference.

Yes.
If the free gifts are not returned in full, their retail value will be deducted from your refund amount.

• Cash on Delivery (COD) Refunds
Once the returned item has been inspected and cleared, refunds will be processed within 7 days. Customers must provide a copy or photo of a bank passbook with a name matching the original recipient. Please note that refunds to third-party bank accounts (accounts not belonging to the recipient) will not be accepted.

• Credit Card / Apple Pay
If you paid via credit card or Apple Pay, we will issue a refund to your original payment method once the returned item is received. Processing time is approximately 7–21 business days. Please check your next two billing statements to confirm the refund. If not found, contact your card issuer.