Permanent Account Number (PAN) is a unique 10-digit alphanumeric identifier issued by the Income Tax Department of India. It is mandatory for filing income tax returns, opening bank accounts, conducting high-value transactions, and business registrations. Individuals, companies, LLPs, firms, and trusts must obtain PAN for financial and tax-related activities. The application can be submitted online or offline with identity and address proof. Accurate documentation ensures quick processing and issuance. PAN also helps track financial transactions and prevent tax evasion.