eSIM Support

How to check if your phone supports eSIM?

 Please check if your device supports eSIM before purchasing.

 You can follow the steps below to verify:

1. Dial #06# on your phone.

If you see an EID number, your device likely supports eSIM.

Note: This method offers an initial check but is not 100% accurate.

 

2. Go to your phone settings and check for options like:

“Add eSIM,” “Add Mobile Data,” or “Add Mobile Plan.”

If available, your device should be eSIM-compatible.

Please confirm before placing your order.

 

How can I check my data usage?

If you’re using an iPhone, please go to Settings → Cellular, scroll down and tap “Reset Statistics” before activating your eSIM.

This will allow you to track your usage under “Current Period”, which shows your total data used.

For Android devices, you can usually check your daily data usage under the Network or Mobile Data settings.

If you have any questions, feel free to contact us via LINE customer support.

LINE ID: @Mars.eSIM

How can I reduce unnecessary data usage?

• App Auto-Updates
  Turn off automatic updates for apps you don’t need to update frequently.

• App Syncing
  Disable background syncing for apps like Google Photos, Gmail, and iCloud to avoid automatic backups and data transfers.

• Auto-Playing Videos
  Apps like Facebook and YouTube may auto-play videos by default. Consider disabling this feature in the settings.

• System & App Updates
  Postpone large software or app updates when using mobile data—set updates to Wi-Fi only.

• Use Free Wi-Fi Whenever Possible
  Connect to local free Wi-Fi to reduce your mobile data usage.

How long does 1GB of Data Last?

How should I choose an international data plan?

If you only need basic connectivity—like sending messages or looking up directions—you’re a Basic User. Less than 500MB per day should be enough.

If you love sharing your trip—using maps, taking photos, and posting them online—you’re a Social Sharer. We recommend starting with at least 1GB per day.

And if you stream videos, attend online meetings, or rely on your phone for work, you’re a Heavy User. A plan offering 1GB or more per day is your best bet.

Just identify your usage style, and you’ll know exactly which Mars eSIM plan to go for!

What Can I Still Do at 128kbps?

When your speed is reduced to 128kbps, you can still send and receive text-based emails and use apps like LINE for sending text messages.

However, loading other websites or using apps that require more bandwidth will be significantly slower, and content may take much longer to load.

Wondering why your internet speed sometimes feels slow?

Network speed may vary depending on factors such as local cell tower coverage, location, terrain, building obstruction, number of users, and weather conditions.

⚠️ Please note: The quality of telecom infrastructure varies by country.
If the actual speed does not meet your expectations, this does not qualify as a valid reason for a refund.

What is the Fair Usage Policy (FUP)?

The Fair Usage Policy (FUP) is a network management rule implemented by local telecom providers to maintain overall service quality.

When a user consumes a large amount of data in a short period — such as streaming videos, live broadcasts, video calls, system updates, or large downloads — and exceeds the carrier’s fair usage threshold, the provider may temporarily reduce that user’s internet speed.

This speed reduction helps ensure that all users on the network continue to enjoy stable and fair internet access.

Do you offer 5G eSIM plans for purchase?

Most eSIM plans offered on the Mars eSIM store support 5G networks, with only a few regions providing 4G service.

Please note that actual internet speed may vary depending on your location, carrier coverage, terrain, building obstructions, number of users, and weather conditions.

Does the plan include a local phone number for calls and text messaging?

Currently, eSIM plans offered on the Mars eSIM store do not include a local phone number for making calls or sending texts.

If you need to make voice calls, please use internet-based messaging apps such as LINE, Messenger, or similar services.

Can I use hotspot sharing with an eSIM?

Yes — all eSIM plans offered on the Mars eSIM store support mobile hotspot sharing.

As long as your device supports Personal Hotspot, you can enable hotspot sharing and let other devices connect.

⚠️ Please note: Using hotspot may lead to faster data consumption. We recommend that each device purchases its own eSIM to avoid exceeding your data limit. ⚠️

Will my app data still be there after installing an eSIM?

Using an eSIM only changes your device’s network connection and does not affect the data or login status of apps on your phone.

⚠️ Please note: App availability and functionality may vary by country due to regional policies. We cannot guarantee that all apps will work internationally. ⚠️

How do I receive Taiwan SMS when I’m overseas?

 ✈️ 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.

Order & Payment

Do I need to sign in or create an account to make a purchase? How can I log in?

You don’t need to sign in or create an account to complete your purchase.

However, creating an account allows you to accumulate your spending and upgrade to a “Mars Navigator” member, enjoying 5% off for one year. Once you’ve placed your first order, your information will be saved for faster checkout next time.

Login options:
1. Log in with your email and password (after creating an account)
2. Log in with Facebook
3. Log in with Google
4. Log in with LINE

What payment methods are available?

• 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.

How do I know if my order was successfully placed?

• After completing your order on the official website, you will receive a confirmation email from no-reply@marsesim.com with the subject line “Order Confirmed.”

• Within 10 minutes, you will receive another email titled “Your eSIM QR Code” containing 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.

I purchased an eSIM, but I haven’t received a uniform invoice. Why?

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.

Will I receive a government-issued invoice for purchasing the Mars eSIM physical card?

Yes, a printed uniform invoice will be sent along with your Mars eSIM physical card.

What is “zero-rated VAT”? Why does it apply to eSIM?

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.

Since no invoice is issued, can I still get a purchase receipt?

Yes! A “Purchase Receipt” (not a uniform invoice) can be provided for each 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.

If I need to include a business tax ID (Uniform Number) and company name, can you assist with that?

Yes. Please provide the following information in the “Order Notes” section during checkout:

• Company Name
• Business Tax ID (Uniform Number)

Can I return or get a refund after purchasing an eSIM?

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.

I purchased an eSIM but my device is not compatible. Can I get a refund?

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.

If I can’t use the eSIM at my destination, can I get a refund?

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.⚠️

Can I get a refund if the product is faulty?

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.).

Can I return a Mars eSIM Physical Card?

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.
• Return shipping costs are the responsibility of the customer.
• Returns will not be accepted if the product is incomplete or the request is submitted after the deadline.
• The refund amount will be the product price minus the original shipping cost paid by our company.

How should I return the product?

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.

Do I need to return all free gifts when making a return?

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

How to Request a Refund & When to Expect It

• 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.

Can’t find the answer you’re looking for?

If you can’t find the information you need,

feel free to click the button at the bottom right to chat with us on LINE — we’re here to help!