Payment schedule for undisclosed income tax requires staged partial payments by specified statutory deadlines to cover tax, surcharge and penalty. Amendment mandates a staggered payment schedule for tax, surcharge and penalty on undisclosed income: at least 25% by 30th November, 2016; at least 50% (reduced by prior payment) by 31st March, 2017; and the balance by 30th September, 2017, substituting the earlier clause in the notification S.O.1830(E).