If you have opened your bank, insurance or stock account between July 2014 and August 2015, you need to submit your Know Your Customer ( KYC ) details and Aadhaar cards by April 30. The tax department has also mandated self-certification of these documents to comply with FATCA regulations (Foreign Tax Compliance Act), failing to which the accounts can be blocked.

The accounts will become operational only after submission of required documents. The new law applies to all accounts that fall under the umbrella of FATCA regulations.

As per the FATCA pact signed by India and the United States, banks and financial institutions were asked to obtain this self-certification for all individual and entity accounts that were opened between July 1, 2014 and August 31, 2015.

It was in July 2015 that India and the US had signed a tax information sharing agreement under a new US law, FATCA. This was done with plans to boost efforts for automatic exchange of financial information between the two nations so that tax evaders can be caught.

Source : http://www.businessinsider.in/linking-aadhaar-cards-to-bank-accounts-mandatory-says-i-t-department/articleshow/58141476.cms