Rule 79 of CGST Rule: Communication and rectification of discrepancy in details furnished by the ecommerce operator and the supplier–
(1) Any discrepancy in the details furnished by the operator and those declared by the supplier shall be made available to the supplier electronically in FORM GST MIS-3 and to the e-commerce operator electronically in FORM GST MIS-4 on the common portal on or before the last date of the month in which the matching has been carried out.
(2) A supplier to whom any discrepancy is made available under sub-rule (1) may make suitable rectifications in the statement of outward supplies to be furnished for the month in which the discrepancy is made available.
(3) An operator to whom any discrepancy is made available under sub-rule (1) may make suitable rectifications in the statement to be furnished for the month in which the discrepancy is made available.
(4) Where the discrepancy is not rectified under sub-rule (2) or sub-rule (3), an amount to the extent of discrepancy shall be added to the output tax liability of the supplier in his return in FORM GSTR-3 for the month succeeding the month in which the details of discrepancy are made available and such addition to the output tax liability and interest payable thereon shall be made available to the supplier electronically on the common portal in FORM GST MIS-3 .