If your income under professional category is over 20 lakhs per annum and you are already filing itr 4, it is mandatory to have a GST number and file returns on monthly or quarterly basis. In that case you need to raise GST invoices to your source of income and pay GST on it.I'm in a similar position where I'm kind of salaried but draw professional fee. I do file using ITR 4, but i don't file any GST returns. What kind of GST do you get? Are we eligible to get GST on profession fee?