A cess imposed by the central government is a tax on tax, levied by the government for a specific purpose. Generally, cess is expected to be levied till the time the government gets enough money for that purpose.
For example, a cess for financing primary education – the education cess (which is imposed on all central government taxes) is to be spent only for financing primary education (SSA) and not for any other purposes.
A cess is different from the usual taxes like excise duty and personal income tax as it is imposed as an additional tax besides the existing tax (tax on tax). For example, the education cess of 3% on personal income tax of 30% is imposed as a tax on the prevailing 30%. As a result, the total tax rate goes up to 30.9% (30% basic rate + 3% (cess) of the 30%).
But some cess like the Swachh Bharat Cess (SBC) is imposed as percentage tax on total value. Here the SBC is 0.5% of the value of the services.
Another difference between cess and the usual tax is the way in which tax revenue from cess is kept. Revenue from main taxes like Personal Income taxes is kept at the Consolidated Fund of India (CFI). The government can use it for any purposes.
But the tax revenue from Cess are first credited to the CFI and the Central Government may, after due appropriation made by Parliament, utilise the money for the specified purposes. For example, the proceeds are kept as Central Road Fund (CRF) in the case of fuel cess (on petrol and diesel). The revenue collected is initially credited to the CFI and after adjusting for the cost of collection, Parliament through its appropriation bill credits such proceeds to the Central Road Fund.
Another major feature of cess like surcharges is that the Centre need not share it with states. But regarding all other major taxes, they come under the divisible pool and hence they shall be shared with the states with the recommendations of the Finance Commission.
At present, the main cess is education cess, road cess or (fuel cess), infrastructure cess, clean energy cess, Krishi Kalyan cess and swachh bharat cess.