People who have taken loans are also supposed to file their Aadhaar details.

Highlights Aadhaar is issued by the Unique Identification Authority of India

Last date to link Aadhaar with PAN is December 31

It is mandatory for processing of income tax returns

Aadhaar, the 12-digit unique identity number issued by the Unique Identification Authority of India (UIDAI), has to be mandatorily linked to permanent account number or PAN and mobile phones. Aadhaar or UID (Unique Identification Number) is based on biometrics-based data. Aadhaar card number or Aadhaar number is also to be shared with financial institutions and has to be submitted to avail the various social security schemes. There are different deadlines for each of these. Here are four important deadlines to remember so that you can smoothly link your Aadhaar:The CBDT (Central Board of Direct Taxes) has extended the last date for linking of Aadhaar with PAN "to facilitate ease of compliance by the taxpayers". The new deadline is December 31, 2017, while the former one was August 31, 2017.Linking Aadhaar-PAN is mandatory for processing of income tax returns (ITRs) for assessment year 2017-18."If this linking (PAN-Aadhaar) is skipped, the return could be considered invalid and the person may have to file it again which shall be considered belated and may attract penalty, interest and other consequences like disallowances for losses," says Sandeep Sehgal, director of tax and regulatory at Ashok Maheshwary & Associates LLP.2.All mobile phone numbers not linked with Aadhaar will be deactivated after February 2018, according to a report by news agency Indo-Asian News Service (IANS) citing sources. That means mobile phone service users will have to link their Aadhaar numbers with mobile numbers. Telecom companies had been earlier instructing users to start the process of linking Aadhaar with phone numbers.Many telecom operators have already started sending alerts to customers about completing the Aadhaar-Mobile number linking process.3.The government has made it mandatory for all banks and financial institutions to mention the Aadhaar details of clients in the KYC (Know your Customer) document. A KYC document basically provides all the details that authenticate the identity of a user. People who have taken loans are also supposed to file their Aadhaar details. If you fail to link it with your bank account by December 31 this year, it may even become inoperable.

4.Your 12-digit Unique Identity Number has to be provided for all social security schemes by December 31, 2017. In order to avail your pension, LPG cylinders or government scholarships, one must provide his Aadhaar card details. (With Agency Inputs)