Permanent Account Number (PAN) is a 10-digit alphanumeric number issued by the Income Tax Department (ITD). PAN is required for all transactions with the ITD, such as filing Income Tax Return (ITR).
A person cannot hold more than one PAN. PAN is required for financial transactions like the purchase of high-end consumer item, foreign travel, with banks, securities, etc.
The ITD uses a PAN to trace a person accounts. These include transactions such as tax payments, TDS, high-value transactions, etc.