As per case facts, the Petitioner received a reassessment notice for AY 2017-18. After initial challenges and subsequent notices, including one under Section 148A(d), the Petitioner filed a CWP which ... was dismissed in view of Supreme Court judgments, affirming the validity of the notice issuance procedure. Later, an assessment order and demand notice were issued. The Petitioner challenged these, arguing that the initial approval for reassessment proceedings was taken from the wrong authority (Principal Commissioner instead of Principal Chief Commissioner) under Section 151 of the Act, especially since more than three years had elapsed from the assessment year, rendering the proceedings void ab initio as per Supreme Court judgments. The question arose whether the reassessment proceedings were validly initiated given the incorrect sanctioning authority. Finally, the High Court held that the grant of sanction by the appropriate authority is a precondition for reassessment. As Section 151 of the new regime specifies Principal Chief Commissioner for periods beyond three years, and the approval was from Principal Commissioner, the non-compliance affects jurisdiction. Therefore, the writ petition is allowed, and the impugned orders and notices are set aside.