Checking on family after a disaster: 171, web171 and the 00000JAPAN Wi-Fi

The short answer

Right after a major disaster, calls into the affected area pile up and struggle to connect. To let people know you are safe, Japan has the Disaster Emergency Message Dial (171), where you leave a voice message, and text-based boards: web171 and the mobile carriers' own disaster message boards.

None of them can be used except during a disaster or on a trial day. The most useful preparation is to try one together on a trial day, such as the 1st or 15th of the month, and to agree on whose phone number everyone leaves messages under.

How the three services differ

Based on the Ministry of Internal Affairs and Communications (MIC) overview:

To use 171, dial 171, press 1 to record or 2 to play back, then enter the phone number the message belongs to. For a landline, include the area code. It works from landlines, payphones and mobile phones, and calls from NTT East or NTT West landlines are free. Check with your carrier about charges from a mobile phone.

Limits and storage periods can change depending on the disaster. According to MIC, the carriers' boards and 171 have been searchable across providers since 2012, so you can find a family member's message by phone number even if you use different carriers.

Trial days

NTT West lists these trial periods for 171:

• The 1st and 15th of every month (00:00 to 24:00)
• New Year (1 January 00:00 to 3 January 24:00)
• Disaster Prevention Week (30 August 09:00 to 5 September 17:00)
• Disaster Prevention and Volunteer Week (15 January 09:00 to 21 January 17:00)

Messages left during a trial are deleted when the trial period ends, and trials may be unavailable while a real disaster is under way. On web171, if you register your user details in advance, you can have a notice sent to chosen email addresses or a phone number when a message is posted.

Using 00000JAPAN

After a major disaster, public Wi-Fi may be opened up free of charge under a shared network name (SSID), "00000JAPAN" (read as "five zero Japan"). According to the Wireless LAN Business Promotion Council (Wi-Biz), since 2023 it can also be opened during a major carrier network outage.

Wi-Biz states plainly that 00000JAPAN has no encryption or other security measures. It asks people to keep use to the minimum, such as checking on others and gathering information, and to be careful about entering IDs, passwords or other personal details and about using financial services. If you have no choice, it recommends HTTPS sites, purpose-built secure apps, or a VPN. In a disaster it is also hard to tell whether a hotspot using the same name is fake.

What to agree on as a family

The Prime Minister's Office disaster page also recommends deciding how family members will confirm each other's safety and where to meet, and knowing more than one method. Agree on these four things:

[Our family contact card]
Number to leave messages under: (e.g.) home landline 0X-XXXX-XXXX
If that number is unusable: (e.g.) Mum's mobile 090-XXXX-XXXX
Order to try: 171 -> web171 -> carrier message board
Meeting place: (e.g.) the playground at ___ Elementary School
Date we practised: ____ / __ / __

If you do not settle on one number, family members may record messages under different numbers and never find each other's. Keep the card in a wallet or work bag so you can read it even when your phone battery is flat.