GSTR 1 is a return form that is supposed to be filed by every registered dealer, who is registered under GST as a regular dealer. This form has two types - monthly or quarterly. If traders or businesses turnover is below 1.5 crores then form will be filed on a monthly basis and if turnover crosses more than 1.5 crores then a form will be filed quarterly. To file GSTR 1 return form there are multiple alternatives in the market.