Frequently Asked Questions

eSIM (embedded SIM) is a digital SIM built into your phone. Unlike traditional physical SIM cards, eSIM doesn't require a physical card - you simply scan a QR code to install and activate it, no SIM swap needed.

ONE card is our upcoming global data eSIM for 200+ destinations, with PAYG billing or optional data packages. Data Only plans are fixed data packages for specific destinations - great value for travelers who only need internet access.

co:sim offers more affordable prices without high roaming fees. You can purchase and install before departure, and start using immediately upon arrival - no need to queue at airports for SIM cards.

Yes! Most eSIM-compatible phones support dual SIM. You can keep your original SIM for calls and SMS while using co:sim for mobile data.

Data Only plans are fixed data packages for specific destinations. You choose the destination, data amount, and validity period. They're perfect for travelers who only need data and want predictable pricing.

No, Data Only eSIMs provide internet data only - no traditional voice calls or SMS. However, you can use apps like WhatsApp, LINE, WeChat, or Skype for voice and video calls over data.

Daily plans (e.g., 1GB/day) reset every 24 hours - great for consistent daily usage. Total plans (e.g., 5GB total) give you a fixed amount to use flexibly throughout the validity period - ideal for variable usage patterns.

For daily plans, some are throttled to lower speeds (e.g., 512Kbps) after the daily limit. For total plans, data service stops when depleted. You can purchase a new plan or use a reloadable eSIM to add more data.

Most plans support hotspot sharing, allowing you to share your connection with other devices. Note that tethering consumes data faster, so consider a larger plan if sharing.

Some destinations support reloadable eSIMs - look for the 'Reloadable' badge on the plan page. Reloadable eSIMs let you add more data without installing a new eSIM.

Most phones released after 2019 support eSIM, including: • iPhone XS and newer • Samsung Galaxy S20 and newer • Google Pixel 3 and newer • Select OPPO, Xiaomi, Huawei, OnePlus, and Motorola models Check our Supported Devices page for the complete list.

Your phone must be 'carrier unlocked' to use eSIMs from other providers. If you purchased your phone through a carrier contract, it may be locked. Contact your carrier to confirm or request unlocking.

Yes! Tablets with cellular capability support eSIM, such as iPad Pro, iPad Air (Wi-Fi + Cellular versions), and Samsung Galaxy Tab S series. Ensure your tablet has eSIM functionality.

iPhone Air is the first Apple phone sold in mainland China with eSIM support. However, it can only install non-Chinese carrier eSIMs when outside mainland China. Other iPhones sold in mainland China don't include eSIM hardware. Some Hong Kong and Macao models may also lack eSIM support. Check your specific model before purchasing.

Installation is simple: 1. Ensure your phone is connected to Wi-Fi 2. Go to Settings > Cellular/Mobile > Add eSIM 3. Choose 'Use QR Code' 4. Scan the QR code we provided 5. Follow on-screen instructions 6. For Data Only: Don't enable data roaming until you arrive at your destination For detailed step-by-step instructions, visit our Installation Guide.

We recommend installing 1-2 days before departure, but don't enable data roaming yet. After arriving at your destination, enable data roaming to start using the eSIM. This ensures the validity period starts from actual usage.

For ONE card, the validity period starts from the date of purchase. For Data Only plans, most start when you first connect to a network at your destination - a few start from the time of installation. The billing start method is noted on the checkout page for each plan.

If installation fails, try: 1. Ensure stable Wi-Fi connection 2. Restart your phone and try again 3. Update your phone to the latest OS version 4. Check that your phone is carrier unlocked 5. Contact our 24/7 customer support if issues persist

If you deleted your eSIM while connected to the internet, you can reinstall it on the same device by scanning the same QR code. However, transferring to a different device is not supported. If the eSIM was deleted while offline, unfortunately customer support cannot restore it. For ONE card cards, you can request a new QR code (including for device transfers) for a fee. For Data Only plans, you would need to purchase a new one.

co:sim uses local carrier networks (4G/5G where available). Speeds are comparable to local users and depend on your location, network coverage, and congestion. Major cities typically offer excellent speeds.

Please check: 1. Data roaming is enabled for the eSIM 2. Airplane mode is off 3. You're within coverage area 4. Try restarting your phone 5. For ONE card: Ensure you have sufficient balance Contact support if issues persist.

Log into your co:sim account on our website to view remaining data, balance, and usage history. For ONE card, you can also dial a USSD code to check balance.

ONE card works across 200+ destinations with one eSIM. Data Only plans are typically for a single destination/region. Some regional plans (e.g., Europe, Asia) cover multiple destinations - check the plan details.

We accept multiple payment methods: • Credit/Debit Cards (Visa, Mastercard, American Express, UnionPay, JCB) • Apple Pay and Google Pay • Alipay and WeChat Pay • Amazon Pay • Crypto and stablecoins (USD only) Available methods vary by region, currency, and device and are shown at checkout.

Immediately after successful payment, you'll receive an email with your QR code. If you don't receive it within 5 minutes, check your spam folder or contact our support.

Yes. After purchase, you can download an electronic receipt from 'My Plans' page. For formal invoices, contact our support team with your order details.

Yes! If you have a ONE card card with sufficient balance, you can use it to purchase Data Only eSIMs. This is convenient when you need a destination-specific data plan.

Uninstalled eSIMs can be refunded unconditionally within 30 days of purchase. Once installed on your device, eSIMs cannot be refunded unless there is a technical issue on our side. See our Refund Policy for full details.

Contact our support via live chat or email with your order number and reason for refund. We'll process your request within 3 business days.

After approval, refunds typically take 5-10 business days to appear in your account, depending on your bank or payment provider.