Interest on delay in gstr 3b

Late fees for GSTR-3B is Rs. 20 (Rs. 10 for CGST and Rs. 10 for SGST) per day for NIL returns and Rs. 50 (Rs. 25 for CGST and Rs. 25 for SGST) in other cases

Late filing fee is applicable on late filing of return.

Interest is paid on the tax amount for the delayed period

CGST & SGST separately. Please note interest is to be calculated on net liability basis, i.e. only on cash paid (not on ITC balance). This was clarified in 39th GST Council meeting, and notifications/orders/law amendments expected for the same.