After finalizing the statements for outward and inward supplies, a registered taxable person has to file the monthly return in FORM GSTR-3. However, the following persons are not required to file the FORM GSTR-3 return:-
(a) Registered taxable person paying taxes under Composition scheme (Form
GSTR-4 to be furnished instead)
(b) Input service distributor (FORM GSTR-6 to be furnished instead)
(c) Non-resident taxable person (FORM GSTR-5 to be furnished instead)
(d) Person liable to deduct tax at source as per Section 51 (FORM GSTR-7 to be furnished instead)
(e) Person liable to deduct tax at source as per Section 52 (FORM GSTR-8 shall be furnished instead)
The return in FORM GSTR-3 will be auto populated from Forms GSTR-1 and GSTR-2.
Further, the details of tax, interest and penalty paid have to be reported in Part B of FORM GSTR-3. The return has to be filed by 20th of the succeeding tax period.
(ICAI FAQ PUBLICATION 06-09-2017 -: Returns : FAQ NO. 15)