St-3 return error

Himanshu (Article Trainee) (97 Points)

25 May 2016  
Sir, We have taken Service Tax No. as Non Assessee so do we required to file Nil return for the same or not ??? And if required, I have downloaded excel utility for half yearly return but it shows "error" that my ST number should be ST001 or ST003 however our ST number ends with SE001. So how could I file the nil return ???