Exemption limit

I need a small clarification in respect of following faxts of the case: 

Client is Registered under the taxable service "Construction of Complex Services" but till now he has not come in purview of this service as he has not constructed any residential building having more than 12 Residential Units. Due to misinterpretation of reading the law One payment of Service tax has already being made on construction of residential building having less than 12 residential units. So the question is :


1) whether he can adjust the Service tax paid in advance as per sub rule (1A) of rule 6 of service tax rules whenever he will construct residential building having more than 12 Residential units? ;

2) Do we need to file Service tax return even if taxable value of service is not more than 10 lakh & Service tax is not payable ? or Intimation to Superintendent of Central Excise for advance payment of service tax is enough?


Kindly reply the query.