Chapter - VIII of CGST Rules, 2017
RETURNS
RULE 73. Matching of claim of reduction in the output tax liability (corresponding section 43)
The following details relating to the claim of reduction in output tax liability 
shall be matched under section 43 after the due date for furnishing the return 
in  FORM GSTR-3, namely:-
(a) Goods and Services Tax Identification Number of the supplier;
(b) Goods and Services Tax Identification Number of the recipient;
(c) credit note number;
(d) credit note date; and
(e) tax amount
Provided that where the time limit for furnishing 
 
FORM GSTR-1 under 
section 37 
and FORM GSTR-2 under 
section 38 has been extended, the date of matching of 
claim of reduction in the output tax liability shall be extended accordingly:
Provided further that the Commissioner may, on the recommendations of the 
Council, by order, extend the date of matching relating to claim of reduction in 
output tax liability to such date as may be specified therein.
 
Explanation.- For the purposes of this rule, it is hereby declared that 
(i) the claim of reduction in output tax liability due to issuance of credit 
notes in 
 
FORM GSTR-1  that were accepted by the corresponding recipient in
FORM 
GSTR-2 without amendment shall be treated as matched if the said recipient has 
furnished a valid return.
(ii) the claim of reduction in the output tax liability shall be considered as 
matched where the amount of output tax liability after taking into account the 
reduction claimed is equal to or more than the claim of input tax credit after 
taking into account the reduction admitted and discharged on such credit note by 
the corresponding recipient in his valid return.