Service tax applicable or not

Hi,

As i mentioned earlier i have joined a startup consultancy firm.

My company made a contract with advertisment ( Print Media )company in which Service tax was not charged from us.

we have made this contract on behalf of our clients now we have to raise invoice to our clients.

and the confusion is that we should charge service tax to our client or not as we havent paid Service tax to the contract company.

Thanks

Ravi Sharma