It is compulsory for
- Service Provider (if taxable turnover of all services > 9 lacs)
- Service Receiver (Compulsory Registration,no limit)
- Input Service Distributor (Compulsory Registration,no limit)
Optional Registration
Some service providers who have just started business also opt for service tax registration even if their turnover has not touched 9 lacs
This is because Service tax registration serve as proof of business and it is easier to apply for current account