Furnishing details of inward supplies: electronic verification, modification and rectification obligations with prescribed deadlines and penalties. Every registered person, excluding specified categories, must verify and prepare inward supply details by validating, modifying or deleting supplier-communicated outward supply information and may include undeclared inward supplies, covering taxable supplies including reverse charge and integrated/customs-taxable supplies. These details must be furnished electronically within the prescribed window in the month following the tax period, with the Commissioner able to extend time; modifications by recipients must be communicated to suppliers. Unmatched entries must be rectified in the period noticed with payment of any tax and interest, subject to a final rectification deadline tied to the year-end return.