After the Assessee has computed his/her Total Income and Tax Liability he has to submit the Return of Income to the Central Board of Direct Taxes. This Return of Income is nothing but a self declaration of Income earned by the assessee and tax liability during the period in a prescribed format provided by the CBDT.
As per the provisions of Income Tax Act, 1961; CBDT notified the format for filing of Return of Income for various Assessees from Individual to Companies, in which they have to present the Total Income and tax liability. In Return of Income the assessee has to show off the particulars of Income earned under different Heads of Income, Exemptions allowed under each Head of Income, Total Income and Tax liability.
Income Tax Act prescribed due dates for filing of Return of Income in case of different assessees. All the Firms and Companies must submit the Return of Income before the due date. But the CBDT may extend the period for filing of Return of Income in case of Firms and Companies. Individuals are exempted from filing, if the income does not crosses the basic exemption limit specified in the Finance Act.