1. If he is just providing service then why has he taken registration if his turnover is below 20 lakh?
Also this option needs to be selected in the start of year and you cant switch from normal scheme to composition scheme between the year but the reverse can be done. But since this is the first year of composition scheme for service provider the date to opt for composition scheme has been kept at 30th September.
2. Yes once you apply for composition supply on your GST number it is applicable on all services you provide.
3. If you are opting for composition scheme you cant charge separate GST nor can you issue tax invoice, you have to issue bill of supply without mentioning GST amount.
4. One cannot transfer GST registration as GST is PAN based registration but you can transfer ITC on sale of busienss using ITC 02 form.
2. Yes they can opt for composition scheme.
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