Aadhaar integration now requires a generated Aadhaar linked within the tax year; unlinked PANs become non operative. Section 262 of the Income Tax Act, 2025 centralizes taxpayer identity as a single Identity Code by incorporating the Aadhaar definition from the Aadhaar Act, shifting the linking obligation to the Tax Year, requiring a generated Aadhaar number (no Enrolment ID), carving out non residents from biometric mandates, employing an authentication model that limits CIDR access, deeming PANs not linked to Aadhaar non operative for transactions, and enforcing strict timelines that preclude curing missed links by revised returns.