Every year, thousands of Chinese-Americans fly back to China and spend the first day scrambling to get connected. The US SIM card barely works, apps are blocked, WeChat Pay won't load, and the roaming bill is alarming. With eSIM technology now mainstream, there's a much better way to handle it — if you plan ahead. Here's everything you need to know before your next trip.
Why Your US SIM Card Isn't Enough in China
Your US carrier's international roaming does technically work in China, but there are several problems:
Cost: Roaming rates on US carriers in China can be high. Even plans that include "international data" often throttle speeds severely or charge per-megabyte overages. Check your specific plan — many AT&T, T-Mobile, and Verizon international plans cap China data at 2G speeds.
App blocking: China's Great Firewall blocks Google services (Maps, Gmail, YouTube), Facebook, Instagram, WhatsApp, and many other apps. Your VPN needs to be installed and tested before you leave the US — it becomes much harder to download and configure once you're inside China.
WeChat Pay recharge: If your WeChat Pay balance runs low, recharging it inside China with a US card can be complicated. Having a local Chinese number linked to your account helps significantly.
Band compatibility: If you recently bought a Chinese-market phone and brought it to the US, it may lack the US LTE bands that your US carrier uses. The reverse is also true — some US-market phones may not support all Chinese 5G bands. Check the specs before you go.
eSIM Option 1: International Data eSIMs (Airalo, Nomad, Holafly)
Services like Airalo and Nomad sell data-only eSIM plans for China that you activate before you leave. The process is simple:
- Download the app (Airalo, Nomad, or similar)
- Purchase a China data plan (pricing varies by provider and data amount — compare at their websites for current rates)
- Scan the QR code or use the app to install the eSIM profile on your phone
- When you land, switch to that eSIM for data
Pros: Easy setup from the US, no Chinese ID required, plans from short-term to multi-week, works immediately on landing.
Cons: Data only — no calls or SMS. You'll still need to use your US number for voice calls (via VoIP, WeChat, or roaming), which can matter if you need to receive SMS verification codes from Chinese services.
Practical tip: These services often offer better speeds than US carrier roaming in major cities because they use local Chinese carrier infrastructure (China Mobile, China Unicom, China Telecom) rather than international roaming agreements.
eSIM Option 2: Chinese Carrier eSIM for US Residents
This is the option most Chinese-Americans don't know about: China Unicom and China Mobile both offer international eSIM plans that US residents can purchase remotely, without being in China.
China Unicom International eSIM: Available through their US app or website. Requires a passport for verification. Provides a real Chinese phone number, voice calls, SMS, and data. Plans typically start from around $10–30/month for travelers, though rates change — check their official US app for current pricing.
China Mobile International (CMLink): Similar offering, available in the US. CMLink specifically markets to overseas Chinese and has English-language customer support.
Why this matters: A real Chinese number means you can receive SMS verification codes for Chinese apps, link to WeChat Pay more easily, and call Chinese domestic numbers at local rates instead of international rates.
How to get one:
- Download the China Unicom International or CMLink app
- Register with your passport (photo ID verification)
- Choose a plan and pay online
- Receive a QR code to install the eSIM profile
- Activate when you arrive in China (or just before departure)
Which Phones Support Dual eSIM?
To run both your US number and a Chinese eSIM simultaneously — the ideal setup — your phone needs to support dual eSIM or a physical SIM + eSIM combination.
iPhone:
- iPhone XS and later support one physical SIM + one eSIM (US models)
- iPhone 14 and later (US models): eSIM only — no physical SIM slot. These models support two active eSIMs simultaneously, making them ideal for international travel.
- iPhone 15 and later: Supports multiple saved eSIM profiles with two active at once
Google Pixel:
- Pixel 3a and later support eSIM
- Pixel 8 and later: Support dual eSIM (two eSIMs active simultaneously)
Samsung Galaxy:
- Most Galaxy S20 and later support eSIM
- Galaxy S24 series: Supports dual eSIM in some configurations (check your model — some markets ship with dual physical SIM instead)
Important: Chinese-purchased Samsung phones often have different configurations from US-market models. If you bought your phone in China and brought it to the US, eSIM support may differ — bring it into our San Gabriel store and we can check compatibility.
How to Add an eSIM to Your Phone
iPhone:
- Settings > Cellular > Add Cellular Plan
- Scan the QR code provided by your carrier
- Follow prompts to label the plan (e.g., "China Travel") and set defaults
Android (Pixel):
- Settings > Network & Internet > SIMs > Add eSIM
- Follow the "Download a SIM" prompts and scan QR code
Android (Samsung):
- Settings > Connections > SIM Manager > Add eSIM
- Scan QR code
Once installed, you can switch between plans in Settings without removing any physical SIM card.
VPN: Set This Up Before You Leave
VPN is outside the scope of eSIM, but it belongs in any China connectivity guide: set up and test your VPN before you leave the US. Apple's App Store inside China does not show VPN apps, and many VPN websites are blocked from inside China. If you leave without one, you may not be able to download or configure one once you arrive.
A working VPN is what makes Google Maps, Gmail, and Western social media accessible inside China.
Maintaining Your US Number While in China
Your US number stays active as long as your US plan continues. To receive calls and texts:
- Wi-Fi Calling: Enable before you leave (Settings > Phone > Wi-Fi Calling on iPhone). With this on, incoming US calls and texts arrive over any Wi-Fi connection at no roaming charge — even from a hotel room in Shanghai. See our Wi-Fi Calling explainer for full setup details.
- iMessage and FaceTime: Work over Wi-Fi regardless of carrier
- WeChat: Your primary communication tool — make sure it's updated and logged in before departure
At Our San Gabriel Store: eSIM Help and Carrier Setup
If you want in-person help setting up an eSIM or switching to a carrier better suited for international travel, our San Gabriel store is an AT&T Authorized Retailer. We can help you:
- Check if your current phone supports eSIM and dual eSIM
- Add an AT&T eSIM profile to a compatible device
- Compare AT&T international plans for China travel
- Port your number if you're switching carriers before your trip
China Travel Connectivity Checklist
Before you board the flight:
- eSIM plan purchased and installed (data eSIM or Chinese carrier eSIM)
- VPN downloaded and tested while still in the US
- Wi-Fi Calling enabled on your US line
- WeChat updated and logged in
- WeChat Pay balance checked (or top up method confirmed)
- Offline maps downloaded for your destination cities (Google Maps offline, or Baidu Maps)
- Emergency contacts saved with country codes
- Phone supports required bands for Chinese 5G/LTE (check specs if in doubt)
If your phone needs any service before the trip — eSIM troubleshooting, battery replacement to ensure it lasts the journey, or a screen repair — book a free diagnostic at iFixForU and we'll have it ready before you leave.
