The Income Tax Department on Friday urged those who deposited "large amounts of cash" post demonetisation and all companies to file their returns by March 31, failing which they may face penalty and prosecution.
It also cautioned eligible trusts, political parties and associations to file their income tax returns by this final deadline and "come clean".
The department, in public advertisements issued in leading dailies, said it was the final call for filing of belated or revised ITRs for assessment years 2016-17 and 2017-18.
It underlined that there was still time for these categories of taxpayers and that they should avoid last minute rush and file the ITRs well before the deadline.
"If you have deposited large amounts of cash in your bank account/made high value transactions, please consider the same while filling your ITRs.
"Non-filing or incorrect filing of return of income may result in penalty and prosecution," the public advisory said.
It said all companies, firms and limited liability partnership concerns were also required to do so.
The deadline is also applicable, it said, to trusts, associations and political parties whose income prior to claim of exemptions exceeds the minimum chargeable to tax.
Individuals and Hindu Undivided Families having income more than Rs 2.5 lakh and senior citizens with income of over Rs 3 lakh (60-80 years of age) and Rs 5 lakh (over 80 years of age) too need to file their returns for the mentioned assessment years, it said.