It was previously clarified in Circular No. 7/7/2017- GST dated 1st September 2017 that errors committed while filling Form GSTR-3B may be rectified while filling Form GSTR-1 and Form GSTR- 2 of the same month. Further, the circular had also clarified that the system will automatically reconcile the data provided in Form GSTR-3B with Form GSTR-1 and Form GSTR-2, and the variations if any will either be offset against output tax liability of the subsequent month of the registered person.