You can rectify mistakes online by following the steps below Step1: Visit income tax site https://incometaxindiaefiling.gov.in/portal/index.do Step 2: Login with your PAN number or register first and then login. Ensure that you have copy of Intimation received from income tax department to enter the CPC acknowledgment number, date of CPC order, field number 18 & 22 of ITD column from the intimation. Step 3: After login - My account - Rectification - Rectification upload and rectification status, then choose rectification upload. Step 4: After submitting the above details, enter the reasons challenging the IT intimation. Like TDS claim amount not considered by ITD needs to be mentioned here. Step 5: An XML file is to be uploaded, which can be downloaded from 'MY RETURN' in your login. The xml needs to be rectified if there is any mistake at your end else upload the same again. After submission take print out for your record. In case you find the above process cumbersome take the help of tax experts who can do it for you specially online website as they are easily accessible and economical i.e. 550/- for filing rectification. The author is Sudhir Kaushik, CFO and tax expert of TaxSpanner. Sudhir has been asociated with many leading publications and writes for them. You can reach him through https://www.taxspanner.com/