The deadline to link Permanent Account Number (PAN) with Aadhaar is December 31, 2025. Failure to link by this date will render the PAN inoperative from January 1, 2026, impacting tax filings, refunds, and financial transactions. A Rs 1,000 late fee applies for linking after the original deadline, though some individuals who obtained PAN using an Aadhaar enrolment ID have until December 31, 2025, to link without a fee. Consequences of an inoperative PAN include delayed refunds, higher TDS/TCS rates, and disruptions to banking and investment activities.