Limitation for reassessment notice is relaxed to implement appellate or court findings, subject to a built-in time-bar safeguard. Notice under section 148 may be issued notwithstanding the ordinary time limit in section 149 where assessment, reassessment or recomputation is required to give effect to a finding or direction in an order passed in appeal, reference or revision by an authority, or by a court. The notice must be issued within three months from the end of the quarter in which the certified copy of the order is received. The relaxation does not apply where, at the time of the relevant order, the assessment year was already barred by another limitation provision.