The Income Tax department has provided a number of ways to do so.
1. Linking your Aadhaar with your PAN using SMS
Send SMS to either 567678 or 56161 in the following format: UIDPAN <SPACE><12 Digit Aadhaar><SPACE><10 Digit PAN>
2. Linking your Aadhaar with your PAN on https://incometaxindiaefiling.gov.in/ without registering
Go to https://incometaxindiaefiling.gov.in/ and click on the banner or the link on the left side saying ‘Link Aadhaar’
Enter your PAN number, Aadhaar and the name exactly as per the Aadhaar card and click on ‘Link Aadhaar’. The linking will be confirmed once the entered details are matched with the UIDAI data.
If Date of Birth and gender is fully matched and name as per Aadhaar is not exactly matched then you will have to additionally provide Aadhaar one time password (OTP) to proceed with partial name match.
3. Linking your Aadhaar with your PAN on https://incometaxindiaefiling.gov.in/ after logging in
Go to https://incometaxindiaefiling.gov.in/ and click on ‘Login Here’
Login to the E-filing website
Click on ‘Link Aadhaar’ in the ‘Profile Settings’ tab
You will be shown your name, date of birth and gender as per the details submitted at the time of registration. Verify that the details on screen match with those in your Aadhaar card. Once you click on ‘Link Aadhaar’ you will be notified if the linking has been successful or not.
In case your Aadhaar and PAN details do not match, you can update them.
To update your PAN details please visit NSDL portal
To update your Aadhaar card details please visit UIDAI portal