Sir, as on now, we have two returns for regular tax payer, GSTR-1 and GSTR-3B, rectification of any omission or addition or deletion, can be done in the subsequent month(s) or quarter(s), means till you file Annual returns, however, not without any restriction or condition. Here I wish to add that the concept of Annual return is taken from State VAT department and any omission or addition can be made in the Annual return, as you cannot amend after the subsequent month or quarter. This to protect revenue and also unwarranted litigation.
At present the amendment can be done in subsequent month(s) or quarter(s). However, the amendment is for subsequent month or quarter. As we know that the quarterly filing of return GSTR-1 or GSTR-3B was not the intention of the Govt. Therefore, if any omission or rectification required, which were not done in the subsequent month or quarter, due to any reason, the Annual Return, where such reconciliation can be made and tax if any to be paid is required to be paid along with interest. As you might have noticed that Govt. intention was change the Accounting year from January to December. In this regards, Section 44 may please be referred. When the designed structure of GST has been distorted due to various factor, many ambiguity has arises. Now it the duty of the intellectuals to bring to the notice of the Govt. the difficulties faced by the tax payers. Please correct me if mistaken.