Form GSTR-3B is a simplified summary return and the purpose of the return is for taxpayers to declare their summary GST liabilities for a particular tax period and discharge these liabilities. A normal taxpayer is required to file Form GSTR-3B returns for every tax period.
All normal taxpayers and casual taxpayers are required to file Form GSTR-3B every time there is an extension of due dates of filing for Form GSTR-1 and Form GSTR-2.
Specified due date for filing of Form GSTR-3B is 20th day of the month following the month (tax period) for which the return pertains. However, due date for filing of Form GSTR-3B can be extended by Government through notification.
Filing of Form GSTR-3B is mandatory for all normal and casual taxpayers, even if there is no business in that particular tax period.