If you need further clarification regarding the process of our working, do watch this video. It is a step by step guide to understand how to apply for GST NIL Filers.
Every registered taxpayer has to file his/her GST Returns on time. The GST Law does not give exemption to taxpayer who have not made any sale/purchase during the month not to file the returns.
Therefore, even in the case of no sale and purchase during the month, the taxpayer has to file the return. Under GST, in order to avoid penalty and further complications, a registered taxpayer strictly needs to file a NIL Return even if there was no business activity (i.e. sale/purchase/transaction) during a month.