GSTR1 MISSED INVOICES OF 2017-2018 Impact on current GSTR3B

I HAVE 3 MISSED INVOICES OF SEPTEMBER 2017 IN GSTR1

AND I WANT TO ENTER THOSE INVOICES IN DECEMBER 2019 GSTR1

tax for those invoices have been timely paid in september 2017 only, so no liability right now.


my query is how do i add those 3 bills in december 2019 return ?

and once i enter those 3 bills in december 2019 gstr1 then will it make any difference in current gstr3b


i just want to make sure that by adding those 3 bills it doesn't increases my tax liability in current Dec gstr3b as tax has been paid already


somebody please guide