Direct from the ATO, here are the key dates for Jan to April 2019 21 Jan 2019 December monthly BAS due 28 Jan 2019 December quarter Super Guarantee (SG) due 04 Feb 2019 Feb Fuel Tax Credit Rates change 21 Feb 2019 Jan monthly BAS due 28 Feb 2019 December quarterly BAS due 28 Feb 2019 December quarterly PAYG instalment due 21 Mar 2019 Feb monthly BAS due 23 Apr 2019 March monthly BAS due 29 Apr 2019 March quart