All the business entities (Company, LLP, and Firm) must file ITR even if their total income or tax payable is zero. In case of an individual, when income exceeds the basic exemption limit, it is recommended to file ITR to avoid scrutiny from the Income Tax Department.

The due dates for filing ITR online are mentioned below – let’s take an e.g. of  (F.Y. 2019 – 20 & A.Y. 2021 – 22)
Up to 31st July of next year (31st July, 2020) – Individuals, HUF, BOI and AOP (who does not fall under the audit provisions)
Up to 30th September of next year (30th September, 2020) – Companies including other entities on which Audit provisions are applicable

Every registered dealer, whether being a normal supplier or otherwise must file the return based on the transactions or activities involved in the business. Non-filing of the same may lead to default and may attract a penalty or additional fees.

You cannot pay the taxes after filing the returns. Instead, it should be paid before the return filing. If it is not done so, the return will be considered invalid