World Data Flat


World Data Flat is an overseas data flat rate service (★1) that allows you to use data communication for 24 hours in eligible countries and regions around the world from the data amount of the Flat-rate Data service or rate plan you subscribe to in Japan by paying a usage fee.

About World Data Flat (in Japanese only)

Eligible customers

You must be subscribed to Data Charge (free).

Data Charge

Usage fee

¥980 (tax exempt)/24 hours

  • *The amount of communication used in World Data Flat is consumed from the monthly data amount of au Adjust Plan, au Flat Plan, Flat-rate Data 1 to 30, Flat-rate Data 1 (Mobile Phone) to 5 (Mobile-phone), LTE Flat, or other domestic flat rate data services or rate plans, or data amounts purchased with Data Charge (★1).


Not required

Eligible countries and regions

Over 150* countries and regions
*Eligible countries and regions have been expanded as of October 11, 2017.

Areas and charges (au World Service)

  • *When the service is launched (May 2017)


[About data communication]

★1: If the amount of communication exceeds the monthly data amount or purchased data amount, the maximum communication speed for sending and receiving will be 128 kbps (a best-effort service). Note that even if the amount of communication is within the contracted data amount, a restriction may be placed on the communication speed as per an overseas carrier's policy.

  • *E-mails from an au mobile phone (including tablets), internet use, and use by tethering are eligible. Voice calls, Video Phone, and SMS (C-mail)/International SMS are not covered.
  • *In countries and regions eligible for World Data Flat, it is the only service available as an overseas data communication service. However, if you do not wish to use World Data Flat, you must apply for the World Data Flat Refusal Option. In such a case, Overseas Double-Teigaku is available.
  • *If you are in an ineligible country or region, you are connected to a ship/airplane carrier, or you are not subscribed to Data Charge, World Data Flat is not applied. Instead, Overseas Double-Teigaku or a pay-as-you-go system is applied to the data communication charge.
  • *Regardless of whether you are subscribed to a data flat rate service, your line may be temporarily suspended if the cost of the packet communication you use overseas becomes high.
  • *Partner carriers, regions, or cities may not be changed or available due to communication circumstances in the destination country or region.
  • *This service may not be available due to terrain or geographical conditions even in available cities or areas.
  • *If using Data Share, the flat rate is incurred for both smartphone and tablet usage.
  • *Even if you are subscribed to Family Discount or Business Discount and the Sharing Course is selected, the amount of unused free call allowances of other family members or other members in the group are not applied.
  • *The monthly basic charge, domestic data flat rate service charges, calling charges, other option charges, universal service fee, and other charges are separately incurred.
  • By phoneOpen 9:00 – 20:00

    • English

      0120-959-472(Toll Free)

    • Portuguese

      0120-959-473(Toll Free)

    • Chinese

      0120-959-476(Toll Free)

    • Korean

      0120-959-478(Toll Free)

    • Tagalog

      0120-933-952(Toll Free)

    • Vietnamese

      0120-933-961(Toll Free)

    • Japanese
      about au mobile services

      157(Toll Free)from au phones

      0077-7-111(Toll Free)

      about Internet services
      Contract / Fee / Billing

      0077-7084(Toll Free)

      Connection setting / failure

      0077-777(Toll Free)