Waiver of time limit under section 154 allows tax officers to cancel penalties after assessments annulled, subject to exceptions. The Board authorises tax officers to take suo motu action or admit applications under section 154 to cancel penalty orders surviving after the underlying assessment has been cancelled or annulled, waiving the time limit under section 154(7) as necessary. Authorities empowered include ITOs, AACs, IACs, Additional Commissioners and Commissioners, with appellate or revision authorities acting where they are the last competent authority. Exclusions: penalties confirmed by higher tribunals, penalties from assessments set aside for de novo framing, and penalties where appeals are pending.