In case of Individuals or Proprietary Concerns and Partnership Firm, service tax is to be paid on quarterly basis. The due date for payment of service tax is the 5th of the month immediately following the respective quarter. For the purpose, quarters are : April to June, July to September, October to December and January to March. However, payment for the last quarter i.e. January to March is required to be made by 31st of March itself. service tax rule 6(1)
Your case need to pay service tax by 5thof the January 2012