If paragraph (1) of the preceding Article applies, the calculation of the tax prepayment calculation base is based on what has been established as of May 15 of the relevant year, and the determination as to whether a person falls under the category of a Resident is based on the person's circumstances as of June 30 of the relevant year; provided, however, that if the amount calculated based on what has been established as of any date between May 16 and July 31 of the relevant year turns out to be less than the amount calculated pursuant to the provisions of the main clause, the calculation of the tax prepayment calculation base is based on what has been established as of that date (or as of the day on which the amount so calculated is the smallest, if there are two or more such dates).
略称規定第百四条第一項・この章の中だけ
居住者(第百七条第一項(特別農業所得者の予定納税額の納付)の規定による納付をすべき者を除く。)は、第一号に掲げる金額から第二号に掲げる金額を控除した金額(以下この章において「予定納税基準額」という。)が十五万円以上である場合には…
わかりやすく言うと
前年分の課税総所得金額に対する所得税額(譲渡所得や一時所得、雑所得などの分は除いて計算)から、前年分に源泉徴収された又はされるべきだった所得税額を差し引いた金額です。これが十五万円以上だと、第百七条の特別農業所得者などを除き、七月と十一月に三分の一ずつ納めます。