Penal Provision in GST

Nil return - 20/- per day ; Not a nil return - 50/- per day along with interest

First of its not penalty... The penalty imposed at the time of Audit and any others...

Now,
Late filing and Late payments related charges are imposed under GST...

Late Fee :

The late fee applicable for GSTR returns not filing in or before due. The late payments are i) Nil Return - Rs. 20/day (CGST Rs 10 & SGST Rs 10). ii) Other than Nil Return - Rs. 50 (CGST Rs 25 & SGST Rs 25)...

Interest (on late payment) :
Interest is applicable for Late Payment of GST. If we are not paid On or before due date then Interest is applicable @ 18% p.a...


As per Your query Interest is applicable if You are not paid GST on or before due date. Also if not filed GSTR return late fee is applicable...