How to calculate late payment fees on MVAT & CST payment? WE want to pay MVAT & CST for the period Oct 12 to Mar 13. The due date for payment is 21.04.2013. But we are unable to pay the same on 21st April. So we are paying the same on today i.e.22nd April. So does we have to pay some late fee for MVAT & CST? How to calculate it? We are private limited company from Mumbai.