GST on commission on mobile sale

sachin parikh (125 Points)

17 July 2020  
My client is having a mobile shop who is registered under GST composition scheme and pays 1% GST on sale of mobile and its accessories. For sale of mobiles he gets scheme discounts through monthly credit note which I would termed it as commission from various supplier (Dealer).
My question is whether he needs to pay GST @ 1% as a composition scheme or any other rate applicable. If yes for other rate applicability then how and where to show income and gst on it as composition dealer only has limited boxes in CMP-08 form which needs to be submitted on quarterly basis.

Please guide.