Fix common issues right at the airport. Follow these quick checks first, then the symptom‑based routes.
Before you start: most issues are tiny setting gaps
A misspelled APN, the wrong data line, or a roaming toggle left off causes most failures. Run the universal checks, then jump to your symptom.
0) Quick triage
- Activation failed
- No Service
- Slow or unstable data
1) Universal checks
- Airplane Mode ON → 10s → OFF
- Set mobile data line to eSIM
- Turn Data Roaming ON if your plan requires it
- Verify APN values letter‑for‑letter (mind stray spaces)
2) iOS fixes
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Settings → Cellular → Mobile Data → choose the eSIM
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Turn Data Roaming ON
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Check APN under Cellular Data Network (copy‑paste to avoid typos)
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Still stuck? Remove the plan and re‑scan the QR
3) Android fixes (Pixel/Galaxy examples)
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Remove the eSIM profile → re‑download
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Set Preferred SIM for data to eSIM
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Pick the correct APN from the list, or add it manually
4) Symptom flows
- Activation failed: switch Wi‑Fi → wait and retry → enter code manually → reboot
- No Service: auto network selection → move to open area → re‑save APN → reboot
- Slow: avoid peaks → cap video quality → restrict background data
5) Area effects
Subways, deep wooden halls at temples, mountains, and event venues can attenuate or congest. Re‑attach on platforms or outdoors.
6) Fast‑track support template
- Device and OS version
- Location and whether indoor/outdoor
- Timestamp and symptom
- Screenshots: line selection, APN, signal icon
7) Prevention
- Activate on stable Wi‑Fi
- Update OS before you travel and reboot once
- Disable video auto‑play to preserve bandwidth
Make Your Japan Trip: Save Smart. Connect Fast.
The real strength of JP-SIM.com is not only its simplicity and convenience, but also its outstanding affordability compared to other options.
No more waiting in long airport lines for a SIM card or carrying a heavy pocket Wi-Fi. With JP-SIM, you can purchase online before departure, scan the QR code, and get connected the moment you land in Japan.
JP-SIM is significantly cheaper than roaming and many competitor services, while still offering flexible plans that match your travel days and data needs. Powered by Japan’s major carrier networks, it provides reliable high-speed coverage across the country—from Tokyo and Kyoto to Hokkaido and rural areas. And with 24/7 multilingual support, even first-time visitors can travel with confidence.
