You can apply on the "Change Method of Payment" [支払方法の変更] page of My au (Web). (Basically, the change will take effect from the payment of the following month after the completion of the procedure.)
Please see below for detailed instructions.
Check the change timing and important points, select the billing code for the procedure, select "Direct Debit" [口座振替] and then tap on "Next" [次へ].
Tap on "Agree and proceed" [同意して手続きに進む].
The screen with the "Eligible Financial Institutions" [ご利用可能金融機関] will be displayed.
Scroll down and select either "Bank" [銀行] or "Shinkin Bank/Credit Union/Worker's Credit Union/Agricultural Cooperative" [信用金庫/信用組合/労働金庫/農業協同組合] in the section to select the financial institution you will use, and tap on "Next" [次へ].
Confirm the important notes and tap on "Submit" [送信].
Tap on the name of the financial institution you will use.
Enter the account holder's name and tap on "Next" [次へ].
Tap on "Go to Financial Institution" [金融機関へ].
From here, you will be redirected to the respective financial institution's website. Please follow the on-screen instructions. For any questions, please contact your financial institution.
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