The deadline to link Aadhaar with Permanent Account Number (PAN) is December 31, 2025. Failure to link by this date will render PAN cards inoperative, impacting tax filings, bank accounts, and investments. The process is mandatory for most PAN holders unless specifically exempted. A Rs 1,000 penalty applies for late linking, though individuals obtaining PAN via Aadhaar after October 1, 2024, may be exempt. Linking can be completed online via the Income Tax e-filing portal.