Let’s say there was increase in GST tax rate from 18% to 20% w.e.f.1.6.2017. What is the tax rate applicable when services provided and invoice issued before change in rate in April 2017, but payment received after change in rate in June, 2017?

hellloooooo

The old rate of 18% shall be applicable as services are provided prior to 1.6.2017.