Don't wait till the last week of July to e-file your return. Vaibhav Sankla said, “The tax department's e-filing website becomes almost inaccessible (due to server overload) during the last few days of July, forcing many to file their returns offline.” Also, if you are using the tax department's pattern, make sure you save the incompletely filled file on your computer's disk. In case you're using private portals, make sure you have saved your changes before you log out.

If you are using a private portal for tax filing, make sure that the portal is a licensed e-Return Intermediary (ERI), which is authorized by the Income Tax Department. You will have access to this information on the website of the portal.

Enter details on housing loan, HRA, tuition fees for children, medical insurance, bank interest income and capital gains to ensure you file the accurate return. Even if you have missed out on filing these details in your investment declaration submitted to the employer, ensure you fill these details at the time of online filing. You will be eligible for a tax refund at a later stage.

Last, beware of emails that land on your inbox with a link to the Income Tax Office website. Don't click on the link before double checking the source of the mail. Vineet Agarwal of KPMG, said, "These should be carefully evaluated as they may be intended to steal your sensitive personal information like credit card details/bank details.”