Difference between casual and non-resident taxable person?
A person who occasionally supplies goods and/or services in a territory where GST is applicable but he does not have a fixed place of business. Such a person will be treated as a casual taxable person as per GST. A person who has place of business in Delhi supplies taxable services in Mumbai where he has no place of business would be treated as casual taxable person in Mumbai.
When a non-resident (i.e. a taxable person residing outside India and coming to India to occasionally undertake transaction in the country) supplies goods/services in a territory where GST applies, but he does not have a fixed place of business in India will be treated as a non-resident taxable person as per GST.