01 January 2015
The requirement of filing of ITR generates from section 139 of the Income Tax Act 1961. Whether filing of return is mandatory or not depends upon whether an individual has 'gross total income' exceeding basic exemption limit or not.
Whereas in the case of assessee being a firm or a company filing of return is always mandatory.
A person can file return on his own even the procedure is not too complex but certainly requires a basic understanding of provisions of income tax law.
You may also take service of a practicing Chartered Accountant or a Tax Return Preparer.