| Event Date | Act | Applicable Form | Obligation |
| 07/10/2019 | Income Tax | Challan No. ITNS-281 | Payment of TDS Deducted in September |
| 07/10/2019 | Income Tax | Form No.27C (TCS) | Submission of Forms received in Sep to IT Commissioner |
| 10/10/2019 | Goods and Service Tax | Form GSTR-8 | Return by e-commerce operators for September. |
| 10/10/2019 | Goods and Service Tax | Form GSTR-7 | Return by Tax Deductors/Collectors for September. |
| 11/10/2019 | Goods and Service Tax | GSTR-1 | Outward supplies of taxable goods and/or services for the Month of September 2019 turnover exceeding 1.5 Cr.) Monthly Return. |
| 13/10/2019 | Goods and Service Tax | GSTR-6 | Return by Input Service Distributor for September. |
| 15/10/2019 | Income Tax | Return No. 27EQ | TCS Return of all collectors for September Quarter |
| 15/10/2019 | Income Tax | Form 16B | Issue of Certificate of TDS on Payment made for purchase of property in August. |
| 15/10/2019 | Providend Fund | Electronic Challan cum Return (ECR) | E-Payment of PF for September. |
| 15/10/2019 | ESI | ESI Challan | Payment of ESI for September. |
| 18/10/2019 | Goods and Service Tax | CMP-08 | Payment of tax for September quarter in case of Composition suppliers. (GSTR-04 to be filed annually by Apr 30) |
| 20/10/2019 | Goods and Services Tax | GSTR-3B | Payment of GST & filing summary return of September by Regular & Casual Suppliers. Last date to claim Input Tax Credit of FY 2018-19. |
| 20/10/2019 | Goods and Service Tax | Form GSTR-5 & 5A | Return of Inward & Outward Supplies for September by Non-Resident foreign taxable person. |
| 30/10/2019 | Company Law | Form no 23 AC & 23 ACA | Balance Sheet in XBRL format.(30 days of AGM) |
| 30/10/2019 | Company Law | Form no 23 AC & 23 ACA | Balance Sheet in Non XBRL format.(30 days of AGM) |
| 30/10/2019 | Goods and Service Tax | GSTR-7 | Monthly Return by Tax Deductor for September. |
| 30/10/2019 | Income Tax | Form 26QB | Deposit of TDS on payment made for purchase of property in September. |
| 30/10/2019 | Income Tax | Form 27D | Issue of TCS certificate for September quarter. |
| 30/10/2019 | Income Tax | Form 26QB | Deposit of TDS/TCS of previous month on purchase of property |
| 31/10/2019 | MSMED, 2006 | MSME Form I | Specified Companies(receiving supplies from Micro & Small whose outstanding dues exceed 45 days) to file details of all outstanding dues to Micro or Small enterprises suppliers for Apr to Sep. |
| 31/10/2019 | Goods and Service Tax | GSTR-1 | Quarterly Return of Outward supplies in Jul-Sep (turnover upto 1.5 Cr.) |
| 31/10/2019 | Income Tax | Form 3CD, 3CA/3CB, 3CEB, Form 29B | E-filing of Tax Audit Report/MAT Audit Report |
| 31/10/2019 | Income Tax | ITR 1 to 7 | Filing of Income Tax returns by Cos, Partnership firms etc. (Audit applicable) |
| 31/10/2019 | Income Tax | Return No. 24Q, 26Q & 27Q | TDS returns for September Quarter by ALL deductors |