If invoices in GSTR-2 do not match with invoices in counter-party GSTR-1, then such mismatch shall be intimated to the supplier. If the mismatch continues even after it is made known to both and still it is not rectified. Mismatch can be because of two reasons. First, it could be due to mistake at the side of the recipient, and in such a case, no further action is required. Secondly, it could be possible that the said invoice was issued by supplier but he did not upload it and pay tax on it. In such a case, the ITC availed by the recipient would be added to his output tax liability, in short, all mismatches will lead to proceedings if the supplier has made a supply but not paid tax on it.