New itservic firm - is service tax registration required ?

Hi,

I have started new Private Limited Company.

When should i go for service tax.

I have got 3 projects. shall i go for service tax now or after a year.

As a new company, i heard that their is a tax exemption for a year up to 20 lakhs of transaction/ services.

Is it true. if not, what is the truth.

My client is asking for service tax number.

If i take service tax, should i file returns monthly ?

Kindly suggest.

Thank you.

Waiting for experts reply.