No service tax on free services. If the value of service is zero then the tax on it say 10% will also be zero. This point has been stated in the case Bharti Cellular Ltd. vs CCE (2005)
You can study the case at following link, specially point 5
https://www.indiankanoon.org/doc/609523/
The circular of board referred in case can be read here -
The provision of free service is mentioned in point 5 (Year 2003 - Circular No.62/2003)
Service tax is payable only after realisation of consideration for service................................in case of free service there is not chances of realisation of consideration......................so no tax
Service tax is payable only after realisation of consideration for service................................in case of free service there is not chances of realisation of consideration......................so no tax
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Thats rite, n also check whether books r on cash or acc