Tax Occasions in September 7th Sept., 2019-Due date for deposit of Tax deducted/collected for the month of August, 2019 10th Sept., 2019 - GSTR-7: Return of TDS (Tax deducted at source) with payment of tax. GSTR-8: Statement by e-commerce operator with tax. 11th Sept., 2019- GSTR-1: Outward Supplies (Monthly by taxable person other than ISD and those under composition scheme) 13th Sept., 2019- GSTR-6 – Input Service Distributor 14th Sept., 2019 - Due date for issue of TDS Certificate for tax deducted under section 194-IA/194-IB in the month of July, 2019 15thSept., 2019 Second installment of advance income-tax for the assessment year 2020-21 .Due date for furnishing of Form 24G by an office of the Government where TDS/TCS for the month of August, 2019 has been paid without the production of a challan 20thSept., 2019- GSTR-3B – Monthly return and payment of tax by taxable person other than ISD and those under composition scheme. 30th Sept., 2019 -Tax deducted at source under sections 194-IA and 194-IB to be deposited. Moreover due date of GST return of Sept. is last date to rectify any error of year 2018-19. One can claim any ITC of 2018-19 , issue any debit/credit note for year , upload any invoice in return otherwise it will blocked after Sept. 19 return, can rectify GSTR-1and reconcile sales amount /ITC /RCM liability with books & GSTR 3B .