11 April 2014
Your laibility for service tax is from the date of invoice.So the service tax was due on 06.02.2014 as per Rule 6 of Service Tax Rules. Return filling date is 25.04.2014 as per Rule 7 of Service Tax Rules Rate of Interest is 18% simple interest from the due date till the date of payment as per section 75 of Finance Act,1994.