171 and web171: leaving word when calls won't connect in Japan

📵 Right after a big earthquake, you try to call your family overseas, but calls keep failing.

Why do phone calls often fail after a major disaster?

✅ The right move: Call traffic to and from the affected area surges, congesting the phone network

Why: After a disaster, everyone calls at once and communication traffic spikes, making it difficult to get through — even where equipment is undamaged. Text messages, messaging apps, and message boards like 171 use capacity more efficiently and are more likely to succeed.

Source (summarized): NTT East — Disaster Emergency Message Dial (171)

🌏 Right after a major earthquake, you want to tell your family back home that you're safe — but voice calls keep failing.

What's the most reliable way to get the message through?

✅ The right move: Send text messages via SMS, messaging apps, or social media — and use the 171 message board if lines stay congested

Why: When call traffic surges after a disaster, text-based messages use the network far more efficiently than voice calls and are much more likely to get through. One short 'I'm safe' message beats fifty failed calls. Japan also opens 171, the Disaster Emergency Message Dial — a phone-based message board whose prompts are Japanese-only — and web171, its internet version, which comes with English guides and is the easier one for visitors. (Activation is announced on TV, radio and NTT's website.)

Source (summarized): NTT East — Disaster Emergency Message Dial (171)

💬 A major earthquake has struck. Your Japanese friend texts: 'If phones stop working, use 171.'

What is 171?

✅ The right move: The Disaster Emergency Message Dial — a voice message board for disasters

Why: 171 is the Disaster Emergency Message Dial: a voice message board provided when a disaster such as an earthquake occurs. You can record a short message about your safety, and others can play it back by entering the same number. It has to be a Japanese number in the disaster area — an overseas number will not work — so agree on one in advance, such as your hotel's. The voice prompts are Japanese-only, so check the English how-to on NTT's site (the source below) before you need it — and web171, the web version of the board, offers English guides as well.

Source (summarized): NTT East — Disaster Emergency Message Dial (171)

☎️ You try dialing 171 on a normal day to test it before your trip.

When does the 171 message service actually operate?

✅ The right move: When a disaster occurs and phone lines to the affected area become hard to get through

Why: 171 is activated when a disaster strikes and communication traffic to the affected area surges, making calls hard to connect. When it starts, NTT announces it on TV, radio and its official website — the 171 page also shows whether the service is currently running. Outside disasters (and scheduled practice days), it isn't in service — so learn how it works before you need it.

Source (summarized): NTT East — Disaster Emergency Message Dial (171)