This shouldn't be much of of a problem. This is usually sent where there is a mismatch between the income tax department records and the return filed. You could follow the steps mentioned below:Go through your Form 16 thoroughly and compare the same with your return filedCheck whether you claimed any loss in that year but filed tour return after the due dateCheck whether you have offered all your income to tax including your FD interest income, if anyCheck if there are any airthmetical errorsOnce you have identified the error, you could rectify by filing a revised return.In case there is no error, you could file a reply to the department explaining the causes along with supportings and also specifying why your claim should be accepted.In case you need further help in this regard, please contact me at anr.invests@gmail.com and provide necessary documents to take this forward.Stay tuned and click on Follow for further updates and information regarding my upcoming blog on investing, taxes and policy review.Disclaimer: The above answer is a personal opinion of the author. This does not provide a binding or legal opinion on the issue and should not be construed to be a professional advice. Please contact a tax expert before taking any position on the above. The answer provided was only for information purposes.