Invoice related information

As per provision of GST law, you can rectify your any mistake / omissions relating to inward Supplies (ITC) or outward Supplies in next year before due date of filing return of September,next year or due date of filing Annual return of that year, whichever is earlier.

So, as per above provision, You can show your invoices (B2B) of F.Y 2019-20 not shown/missed to show in F.Y 2019-20, in GSTR 1 or in GSTR 3b of june 2020 and pay tax thereon along with interest.