As per case facts, the petitioner filed an income tax return. Later, the Assessing Officer reopened the assessment and initiated penalty proceedings based on received information. The petitioner contended that ... no notice for reassessment or the assessment order was served, and he only learned of it during recovery actions. However, the petitioner admitted participating in penalty proceedings, implying prior knowledge. The question arose whether an assessment order is invalid due to non-service of the statutory reassessment notice, despite the notice being 'issued' within the limitation period and the assessee having some awareness. Finally, the Court ruled that while the reassessment notice was issued timely, the lack of proven service of this primary notice violated natural justice. Despite the petitioner's later knowledge, the non-demonstration of proper initial service made the assessment order unsustainable. The order was set aside, and the matter remanded for fresh assessment after due service and opportunity for the petitioner to present their case.