Furnishing details of inward supplies requires electronic reporting, recipient verification, supplier communication and rectification with tax payment. Registered persons (with specified exclusions) must verify and adjust details of outward supplies and related credit or debit notes to prepare inward-supply records and electronically furnish details of inward taxable supplies, supplies under reverse charge, integrated-taxable supplies and related credit or debit notes within the prescribed monthly window; modifications by recipients must be communicated to suppliers, and unmatched or erroneous entries must be rectified with payment of tax and interest within the prescribed period and before the post financial year cut off.