Gst registered doubt

kollipara sundaraiah (B.com) (2957 Points)

25 September 2022  
A logistic services (courier service) non registered dealer sec 74 sec 142 notice received from gst department
year:20-21 turnover show in it returns rs:45 lacs
year:21-22 turnover show in it returns rs:50 lacs
tax :18 percentage show in notice
question:
dealer gst registered and tax pay compulsory in gst act