Important dates of September, 2019 for compliance under GST are as follows:-
| Due date | Forms | Period | Description |
| September 10, 2019 | GSTR-8 | August 2019 | E-Commerce operator registered under GST liable to TCS |
| September 20, 2019 | GSTR-1 | July 2019 | Taxpayers in Jammu and Kashmir and 58 flood affected districts across 7 states, having turnover of more than Rs. 1.50 crores or opted to file monthly Return |
| September 11, 2019 | GSTR-1 | August 2019 | Taxpayers having turnover of more than Rs. 1.50 crores or opted to file monthly Return |
| September 20, 2019 | GSTR-6 | August 2019 | Input Service Distributor registered in Jammu and Kashmir and 58 flood affected districts across 7 states. |
| September 13, 2019 | GSTR-6 | August 2019 | Every Input Service Distributor |
| September 20, 2019 | GSTR-3B | July 2019 | Taxpayers in Jammu and Kashmir and 58 flood affected districts across 7 states |
| September 20, 2019 | GSTR-3B | August 2019 | All registered Persons to pay GST and file Monthly GST Return |
| September 20, 2019 | GSTR-5 | August 2019 | Non-resident person pay GST and file Monthly GST Return |
| September 20, 2019 | GSTR-5A | August 2019 | Non-resident ODIAR services provider file Monthly GST Return |
| September 20, 2019 | GSTR-7 | July 2019 | Taxpayers in Jammu and Kashmir and 58 flood affected districts across 7 states |
