Reverse charge on construction inputs requires promoters to pay tax on specified shortfall supplies from unregistered suppliers. Notification under section 9(4) of the Maharashtra GST Act directs that specified registered persons shall pay tax on reverse charge basis as recipients for supplies from unregistered suppliers in the real estate sector, covering: (i) supplies constituting the shortfall from the promoter's minimum purchase obligation for a project, (ii) cement forming part of that shortfall, and (iii) capital goods supplied to a promoter for construction of a project where tax is payable at the prescribed rates; key terms including promoter, project, REP, RREP and FSI are defined.