Defective notice U/S 139(9):

A taxpayer may get a defective notice U/S 139(9), when the information provided by him is either missing or incorrect.

The reasons may include:

• When a tax payer not mentioned his PAN number.
  
  
• There may be some other reasons such as mismatch in the details of tax paid, wrong BSR code, wrong date of challan, inappropriate refund claimed, mismatch in name, mismatch with 26AS etc.
  
  
• When the income in form 26 AS, does not match with the filed ITR.
  
  
• When you have not paid your taxes in full and filed the return.
  
  
• The name mentioned on the Income-tax Return does not match with the name on the PAN card.
  
  
• Not filling of all necessary annexure, statements in the Income tax return.
  
  
• ITR filed is incorrect in terms of the turnover/ income limit.
  
• TDS amount not matching with form 26AS.
  
  If the defect is not rectified within 15 days/ as the case may be, the return filed by the assessee shall be treated as invalid return.