In general, businesses which provide a service that does not result in a tangible good are exempt from sales tax, as it only applies to goods. For example a freelance writer or a tradesperson is not required to remit sales tax, although a carpenter making custom furniture is so required.
The statewide tax rate is 7.25%. In most areas of California, local jurisdictions have added district taxes that increase the tax owed by a seller. Those district tax rates range from 0.10% to 2.00%. Some areas may have more than one district tax in effect.