Don't Panic — It's Almost Certainly Fixable
You just landed in China. You're excited. You walk out of the airport, open your phone to pull up directions to your hotel, and… nothing. No signal. No data. Just a frustrating little "No Service" where your carrier name should be.
Take a breath. This happens to a lot of travelers, and the vast majority of eSIM issues are solved in under five minutes with nothing more than a few taps in your phone's settings.
This guide walks you through every common China eSIM problem — no signal at all, signal bars but no internet, painfully slow speeds, installation failures, connections that keep dropping, QR codes that refuse to scan, and provider-specific quirks. For each problem, we give you the fixes in the exact order you should try them.
Two quick notes before we dive in:
If you haven't set up your eSIM yet (or aren't sure you did it right), start with our complete China eSIM setup and activation guide — getting it installed correctly prevents most of these headaches.
If you haven't bought an eSIM yet, check out our best eSIM for China buying guide to make sure you pick a provider that fits your phone and travel plans.
Quick Diagnostic: Which Problem Do You Have?
Start here. Match your symptom to the problem number, then jump straight to that section.
| Your Symptom | Go To |
|---|---|
| No signal bars at all — "No Service" or "SOS Only" | Problem 1 — No Signal |
| Signal bars showing but nothing loads | Problem 2 — Signal But No Internet |
| Internet works but painfully slow | Problem 3 — Slow Speeds |
| Can't install the eSIM — QR gives error or won't download | Problem 4 — Installation Failures |
| Connection keeps dropping | Problem 5 — Unstable Connection |
| QR code won't scan | Problem 6 — QR Code Problems |
| Worked fine, then speed dropped suddenly | Provider-Specific Issues |
Nine times out of ten, the problem is either Problem 1 or Problem 2.
Problem 1: No Signal After Activation ("No Service")
You've activated your eSIM, but your phone shows zero signal bars. Here's what to try, in this exact order:
Fix 1 — Toggle Airplane Mode (Fixes 60%+ of Cases)
This sounds too simple to work — but it does. Turn Airplane Mode ON, wait a full 30 seconds, then turn it OFF. Don't shortcut the wait time. Your phone needs those seconds to drop its old network search and start fresh.
Give it another 30–60 seconds after toggling off. If signal bars appear, you're done.
Fix 2 — Confirm the eSIM Is Your Active Data Line
Your phone might be trying to use your home SIM instead of the eSIM.
- iPhone: Settings → Cellular → Cellular Data → select your eSIM line
- Android: Settings → Network & Internet → SIMs → select the eSIM for data
Fix 3 — Make Sure You're in the Coverage Country
Some eSIMs won't register on any network until your phone physically detects it's in the destination country. If you installed the eSIM at home (recommended), it may show "No Service" until you actually land in China.
Fix 4 — Restart Your Phone Completely
Not just sleep/wake. A full power-off restart. Hold the power button, shut down completely, wait 10 seconds, power back on. This forces the phone to re-initialize the eSIM profile and renegotiate with local towers.
Fix 5 — Verify Your Phone Supports eSIM
Dial *#06# and look for an EID number. If you see one, your phone supports eSIM. If not, your phone likely doesn't have eSIM hardware.
For a full list of supported devices and common compatibility gotchas, see our China eSIM phone compatibility guide.
Problem 2: Signal Bars But No Internet
This is the most common issue travelers run into. Signal bars are showing — maybe even a carrier name like "China Mobile" — but nothing loads. Here are the fixes in order:
Fix 1 — Turn On Data Roaming for the eSIM (The #1 Cause)
Travel eSIMs connect through roaming agreements with local Chinese carriers. If Data Roaming is off, your phone sees the network but refuses to send or receive data.
- iPhone: Settings → Cellular → tap your eSIM line → turn Data Roaming ON
- Android: Settings → Network & Internet → SIMs → tap your eSIM → turn Roaming ON
Yes, "Data Roaming" has a scary reputation from the days of $20/MB charges. With a travel eSIM, roaming is how the service works — you're not paying extra.
Fix 2 — Turn OFF Data Roaming for Your Home SIM
While you're in settings, make sure Data Roaming is OFF for your physical SIM. This prevents accidental roaming charges on your home carrier.
Fix 3 — Check and Set the Correct APN
If Data Roaming is on and you still have no internet, the APN is the next suspect.
- iPhone: Settings → Cellular → tap your eSIM → Cellular Data Network → check the APN field
- Android: Settings → Network & Internet → SIMs → tap your eSIM → Access Point Names
Enter the APN value your provider gave you (usually in their setup email). Leave username and password blank unless told otherwise. Do NOT modify MCC or MNC fields — changing these breaks your connection entirely.
For a detailed walkthrough, see our China eSIM APN settings guide.
Fix 4 — Disable Data Saver / Low Data Mode
- Android: Settings → Network & Internet → Data Saver → turn OFF
- iPhone: Settings → Cellular → tap your eSIM → turn Low Data Mode OFF
Fix 5 — Toggle Airplane Mode After Any APN Change
If you changed the APN, toggle Airplane Mode ON for 30 seconds, then OFF. APN changes often don't take effect until the phone re-registers on the network.
Problem 3: Slow or Throttled Speeds
Your eSIM works, but everything feels like it's loading through molasses. Usually fixable.
1. Switch from 5G to 4G/LTE
This sounds counterintuitive, but in many Chinese cities, 5G signals are surprisingly spotty indoors and in subways. Your phone latches onto a weak 5G signal and refuses to let go, giving you worse speeds than a solid 4G connection.
- iPhone: Settings → Cellular → Cellular Data Options → Voice & Data → LTE
- Android: Settings → Network & Internet → Mobile Network → Preferred Network Type → LTE/4G
2. Check for Fair Usage Policy (FUP) Throttling
Many "unlimited" plans aren't truly unlimited at full speed:
- Holafly throttles to ~1 Mbps after 90 GB/month
- Saily throttles to 1 Mbps after 5 GB/day
Check your provider's fine print and your current data usage in their app.
3. Close Bandwidth-Heavy Background Apps
Auto-updates, cloud photo sync, and video autoplay quietly eat your bandwidth. Pause auto-updates, disable cloud sync temporarily, and turn off video autoplay.
4. Test at Different Times of Day
Network congestion is real in China — speeds during evening hours (7–11 PM) can drop significantly in dense areas. Run a speed test morning and night to compare.
For more details, see our China eSIM coverage and speed guide and data plans comparison.
Problem 4: Cannot Install the eSIM
You're ready to get connected, but the eSIM won't install. QR code won't load, app throws an error, or the download just hangs.
The Most Common Cause: You're Already in China
Many eSIM providers geoblock their download servers from Chinese IP addresses. The fix: install your eSIM before you travel.
Already in China? Your options:
- Use layover WiFi. If transiting through Hong Kong, Tokyo, or Seoul, install the eSIM using airport WiFi before your connecting flight.
- Use a VPN. If you have access to a VPN and WiFi, connect through a non-China server and try again.
- Saily specifically: The Saily app is blocked inside China. Try their web portal at saily.com through a VPN.
Other Installation Issues
- QR code won't download? WiFi might be weak. Move closer to the router and retry.
- "Carrier locked" error? Contact your carrier for an unlock — usually free if your phone is paid off.
- "eSIM not supported" error? Your phone may not support eSIM hardware.
Our pre-arrival activation guide walks you through the entire setup process.
Problem 5: Connection Keeps Dropping
Your eSIM works… mostly. But the connection drops every few minutes and pages half-load.
1. Turn Off Automatic Network Selection
By default, your phone hops between carriers (China Mobile, China Unicom, China Telecom), causing brief disconnections each time. Lock it to one carrier.
- iPhone: Settings → Cellular → Network Selection → turn off "Automatic" → choose China Mobile or China Telecom
- Android: Settings → Network & Internet → Mobile Network → turn off "Automatically select" → pick a carrier
2. Toggle Airplane Mode
Flip it on for 10 seconds, then off. Forces a fresh network registration.
3. Check Your Surroundings
Basements, elevators, subway tunnels, and thick concrete buildings are dead zones for any cellular signal. Step outside or near a window.
4. Switch to 4G
If drops happen on 5G, switching to LTE gives a more stable connection. See Problem 3 for steps.
Problem 6: QR Code Not Working
The QR code won't scan, or it scans but throws an error.
QR Codes Are Single-Use
Once an eSIM QR code has been successfully scanned, it can't be used again. If you accidentally deleted your eSIM profile, the original QR code is dead — contact your provider for a replacement.
Quick Fixes
- Increase screen brightness — dim screens cause scan failures
- Clean your camera lens — a smudge can prevent a clean scan
- Screenshot and zoom — take a screenshot of the QR code, zoom in slightly, and scan from that
Manual Installation Fallback
If the QR code absolutely won't work, use manual SM-DP+ installation:
- iPhone: Settings → Cellular → Add eSIM → "Enter Details Manually"
- Android: Settings → Network & Internet → SIMs → Add SIM → "Enter manually"
You'll need three values from your provider's confirmation email: SM-DP+ Address, Activation Code, and sometimes a Confirmation Code. They're case-sensitive — enter them exactly.
Provider-Specific Issues and Quirks
Not all eSIM providers play by the same rules. Each has its own gotchas.
Holafly
"Unlimited" plans have a Fair Usage Policy — throttled to ~1 Mbps after 90 GB/month. Hotspot and tethering are capped at 500 MB–1 GB/day, even on unlimited plans. If speed suddenly drops mid-trip, you likely hit the FUP cap. No fix except waiting it out.
Airalo
Plans are fixed-data — no unlimited option. If internet stops completely, you probably burned through your data allowance. Open the Airalo app, check your balance, and purchase a top-up.
Saily
"Unlimited" plans give 5 GB/day at full speed, then throttle to 1 Mbps. The bigger issue: the Saily app is blocked inside China. Use their web portal instead. You must purchase and install before arriving.
Nomad
Cannot purchase new eSIM plans from inside mainland China (app and website blocked). However, if you already have an active plan, you can purchase data add-ons while in China. Install and activate before departure.
When to Contact Support
If you've tried every fix above and nothing works, it's time to contact your provider. Gather this info first — it'll cut your resolution time in half:
- Provider name and plan type (data amount, duration)
- Phone model and OS version
- Exact error message or behavior
- Screenshots of your cellular settings
Most providers offer 24/7 live chat:
| Provider | Typical Response |
|---|---|
| Airalo | ~5 minutes |
| Holafly | ~10 minutes |
| Saily | ~15 minutes |
| Nomad | ~15 minutes |
If support can't fix it, ask for a refund. Most providers offer full refunds if the eSIM never worked properly.
Prevention Checklist
Run through this before you fly and you'll avoid 90% of common China eSIM problems:
- ☐ Install your eSIM before departing — at home, on reliable WiFi
- ☐ Verify eSIM compatibility — dial
*#06#, check for EID - ☐ Confirm carrier unlock — locked phones won't accept third-party eSIMs
- ☐ Screenshot your QR code + save manual activation code
- ☐ Note the correct APN from your provider before traveling
- ☐ Keep eSIM disabled until you land in China
- ☐ Enable Data Roaming on eSIM immediately after landing
- ☐ Disable Data Roaming on home SIM to avoid surprise charges
- ☐ Switch to 4G/LTE if 5G is unstable
- ☐ Test connection right away — try loading google.com
- ☐ Download provider app and offline maps before departure
Most China eSIM problems are solved in under 5 minutes. The #1 fix is toggling Airplane Mode. The #1 prevention is installing before you travel.
For complete setup instructions, see our China eSIM setup guide and phone compatibility guide.