Recovery of self-assessed tax: officers may seek explanation or payment before initiating recovery under section 79. Where outward supplies declared in GSTR-1 are not paid through GSTR-3B, the proper officer shall communicate with the registered person to pay the short-paid amount or explain the discrepancy within a prescribed reasonable time. If the explanation satisfies the officer or the shortfall is paid, recovery need not follow. Failure to respond, to pay within the time allowed, or to justify the difference to the officer's satisfaction permits initiation of recovery proceedings under the statutory recovery provisions.