Registration
GST registration is mandatory for businesses with a turnover exceeding Rs.20 lakhs for Services Sector (10 lakhs for special category states) or Rs. 40 lakhs for goods.
Cancellation
Cancellation can be done from the GST Portal using Form GST REG-16 if your business closed down unfortunately for any reason, you will first need to file all your pending returns and reverse ITC balance on the portal or that ITC balance will permanently lapse once the cancellation is finalized. After that, the GST inspector will review your application. They may also ask you for few documents, such as your bank statements, Income Tax Return and ask for the reason behind closing the business. If the GST inspector finds everything correct, they will approve the application and your GST number will be cancelled. After your GST number is cancelled, you must file your final return in Form GSTR-10. Only then will your work be considered complete. If you do not do this, your number will show as cancelled, but it will not be considered permanently or legally closed. You must file Form GSTR-10 within 90 days, otherwise, you can face a penalty of up to Rs 10,000.