Unlimited Calling Plan S(Smart phone)

New applications are no longer accepted as of August 31, 2019

Unlimited free domestic calls (up to five minutes) 24 hours a day!
In addition, domestic calls made between family members that exceed 5 minutes are also free! (When 2-year contract + Family Discount are applied)

Application Required


Unlimited Calling Plan S(Smart phone) must be subscribed in combination with Flat-rate Data 1/3/5/8/10/13/20/30. (The Unlimited Calling Plan S(Smart phone) service cannot be used in combination with LTE Flat.) A subscription to LTE NET (¥300/month) is required for internet connection.

* The names of rate plans and data flat rate services for 4G LTE (au VoLTE) Android™ smartphones have "(V)".

Rate plan image Rate plan image

Basic charge

Monthly basic charge When 2-year contract [1] is applied ¥1,700
Before application for various discount services ¥3,200
Domestic calling charge To au mobile phones Calls up to 5 minutes: Free
Calls that exceed 5 minutes: ¥20/30 seconds
Calls made between family members that exceed 5 minutes are also free[2]
To other carriers' mobile phones or landline
Data communications charge Select from Flat-rate Data
Domestic SMS (C-mail) To au mobile phones Sending: ¥3/time Free for family members [3]
Receiving: Free
To other carriers' mobile phones and PHS
  • * When you subscribe to this plan, any currently applied discounts may be terminated. See below for details.

Applicability of discounts and campaigns (in Japanese only)


  • [1]2-year contract is automatically renewed in two-year units. In the case of contract termination, a contract cancellation fee of ¥9,500 is incurred (excluding the renewal period).
    The following discount services also apply.
    -Monthly basic charge when 2-year contract (No automatic renewal) is applied... ¥2,000/month
    • * The month following the month of application is counted as the first month, and a contract cancellation fee (¥9,500) is incurred if the contract is cancelled within 2 years.
    -Monthly basic charge when Smile-heart Discount is applied... ¥1,500/month
  • [2]When 2-year contract (Smile-heart Discount or 2-year contract (No automatic renewal)) + Family Discount are applied, calls made to family members who are subscribed to the same Family Discount are free.
    2-year contract + Family Discount
  • [3]Sending SMS (C-mail) to family members within Japan is free when Family Discount is applied.
    Family Discount

★This is not applicable to some calls.

Click here for more details

Combined as a set with Flat-rate Data

  Data quantity Monthly charge Monthly total [4] Availability of Data Carryover [5]
Flat-rate Data Flat-rate Data 1(1GB) [6] ¥2,900 ¥4,900~ -
Flat-rate Data 3(3GB) ¥4,200 ¥6,200~ -
Flat-rate Data 5(5GB) ¥5,000 ¥7,000~
Flat-rate Data 8(8GB) ¥6,700 ¥8,700~
Flat-rate Data 10(10GB) ¥8,000 ¥10,000~
Flat-rate Data 13(13GB) ¥9,800 ¥11,800~
Flat-rate Data 20(20GB) ¥6,000 ¥8,000~
Flat-rate Data 30(30GB) ¥8,000 ¥10,000~
  • * As of September 14, 2016, new applications (including changing contracts) for Flat-rate Data 8 to 13 are no longer accepted. Customers who are currently using the plan may continue to use it.
  • * Flat-rate Data 2 cannot be chosen.
  • [4]The sum of Unlimited Calling Plan S(Smart phone) (¥1,700/month) and LTE NET (¥300/month)
  • [5]For Flat-rate Data 5/8/10/13/20/30, the unused data amount in a month can be carried over and used by the end of the next month.
    Data Carryover
  • [6]Monthly discount is not applicable.

Even greater savings when combined with au Smart Value! Click here for details

Eligible models

Unlimited Calling Plan S Unlimited Calling Plan S (V)
4G LTE (excluding au VoLTE) smartphone 4G LTE (au VoLTE) smartphone
iPhone (excluding iPhone 4S) * This service is not available for 4G LTE(au VoLTE supported) mobile phones and 3G mobile phones.
* This service is not available for 3G mobile phones.

Related services

You can purchase data quantity starting from 0.5GB using the Data Charge service when needed.

You can purchase as much data quantity as you need (in 0.5GB or 1GB units) in real time when you need it. You do not need to worry even if you use a lot of data.

Data Charge

Data Present allows you to give purchased data to friends and family.

Give newly purchased data to friends and family. The person who receives the Data Present can increase the data amount they use by the amount given.

Data Present

Data Gift allows family members to give data quantities to each other without waste.

The Data Gift service allows family members to give the monthly data quantities (in 0.5GB units) to each other in real time at no additional charge, ensuring that extra data quantities are used without going to waste.

Data Gift

Long Term Hospitality Data Gift gives long-term customers extra data amounts.

Long-term au customers will receive an extra data amount once every 3 months according to the au contract period (5 years and over) and subscribed Flat-rate Data service.

Long Term Hospitality Data Gift

Universal service system

In accordance with the launch of the "Universal Service System", KDDI has begun imposing a "Universal Service Fee" on customers who signed contracts with us for their portion of usage since January, 2007.
See below for the details.

Universal service system


[Unlimited Calling Plan S(Smart phone)]

  • Flat-rate voice calls with this plan do not apply to voice calls to phone numbers starting with 0180, 0570 or other numbers that are charged by other carriers, voice calls to directory assistance (104), 1XY administration number services (188/189), SMS transmissions, voice calls to satellite phones/ship satellite phones, and voice calls to phone numbers that KDDI separately determines. Also, international calls and calls made to and from overseas are not applicable. In addition, flat-rate voice calls with this plan may not apply in the following situations.
  • When using a mobile phone subscribed to this plan to connect to the customer's own communications equipment or to make an automatic call using software (except with the prior approval of KDDI in either case)
  • When using Unlimited Calling with the aim of gaining direct income from communications through communication mediation, use of the forwarding function or connecting to a service provided by another company
  • When using Unlimited Calling for purposes other than voice calls
  • A calling charge of ¥20/30 seconds is incurred for domestic calls that are not eligible for free calls if other carriers do not set their rate (Satellite calls to ships incurs a charge of ¥50/30 seconds).
  • Calling charge discounts that are provided by "2-year contract (Smile-heart Discount or 2-year contract (No automatic renewal)) + Family Discount" or "au → My Home Discount (if free)" are applied. Calling charge discounts that are provided by "au → My Home Discount (50% discounts)", "Smile-heart Discount", and other discount services are not applied. Calls that exceed 5 minutes incur a calling charge of ¥20/30 seconds.
  • * Should KDDI judge, for example, that a continuous call for a long period of time is affecting KDDI equipment, the call in question may be terminated.
  • * Numbers that are specified by KDDI (such as the ones that are connected when using a telephone service provided by a carrier other than KDDI, and the ones that are continuously connected for a specified period for long-term or multiple communications due to a call that originates by a mechanical nature) are not eligible for flat-rate calls.

[Flat-rate Data]

  • * If using World Data Flat, the data amount is consumed from the monthly data amount of the domestic data flat rate service. If using Two-step data flat for Overseas, charges are incurred for communications used overseas. Does not apply to use of domestic monthly data amount.
    World Data Flat
    Two-step data flat for Overseas

[Application of Charges]

  • If applying when making a new subscription or switching models, the rate plan and Flat-rate Data service become applicable from the date of subscription or the date of switching models (the basic charge/Flat-rate data charge is prorated). If changing the contract or switching to a model you bring to a shop, the service becomes applicable from the month following the month of the change or switch. If you cancel in the middle of a month, the rate plan and Flat-rate Data service charges are not prorated and the flat rate is incurred (If not subscribed to 2-year contract or 2-year contract (No automatic renewal), the basic charge is prorated.).
  • Check for other costs arising from the contract at the store.

[Restrictions of communication speed]

  • * If the total amount of communications of the month exceeds the data quantity for that month, the maximum communications speed for sending and receiving until the end of that month will be 128 kbps. (The communications speed constraint will be removed on the first day of the following month.) If you apply for the Extra Option, the communications speed constraint does not apply. Data quantities purchased with Data Charge can be used without any communications speed constraint.
    Extra Option
  • * To avoid network congestion, a limit may be placed on the communication speed for a whole day if the total amount of communication used exceeds 6GB over the three most recent days (not including the day on which the restriction is applied). The restricted speed will differ depending on data traffic conditions.
    (The restriction applies regardless of the remaining data amount.)
  • Regardless of whether you are subscribed to a Flat-rate Data service, your line may be temporarily suspended if the cost of the packet communications you use becomes high.

[Communication amount notification]

<When using Flat-rate Data>

  • * Customers are notified via SMS (C mail) when the remaining amount of their monthly data amount drops below 10% or reaches 0% during the current month.

<When using Data Charge>

  • * Customers whose total monthly data quantity and purchased data quantity for a given month is 5%,1% or lower will be notified by email to the mail address registered to the au ID.
  • 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)