Furnishing details of inward supplies: recipients must file and reconcile monthly inward-supply details within prescribed filing window. Registered persons, excluding specified classes, must electronically furnish and reconcile details of inward supplies-including reverse-charge and integrated-taxable supplies-and related credit/debit notes between the 11th and 15th day of the month following the tax period, with the Commissioner empowered to extend the deadline; modifications by recipients must be communicated to suppliers, and unmatched items must be rectified and any short payment of tax and interest paid in the period in which the error is discovered, subject to a cut-off at the September return or the relevant annual return, whichever is earlier.