Linking Aadhaar with various services has become mandatory now. There are a host of services for which the Aadhaar linking would need to be done. Here is the list of services that would require Aadhaar linking. Deadline for PAN December 31 2017 Linking Aadhaar with PAN is mandatory for process of income tax returns. While the Centre has told the Supreme Court that February 6 is the last date to link Aadhaar with Mobile, the DoT recently said that it is not mandatory as of now. Once the SC decides a final call would be taken. To link go to your telecom operator shop with Aadhaar Card. Deadline for Bank account December 31 2017: After Dec 31, 2017, your bank account will cease to be operational if it's not linked with Aadhaar. Also the government won't open any account which doesn't fulfill Aadhaar-based Know Your Customer(KYC) process. The same is needed for investing in a mutual fund.