GST is a unified tax on all supplies of goods and services. It replaces various indirect taxes being levied on goods and services by the central and state governments. This is destination of consumption based tax. Under GST there are four components- state GST, central GST, union territory GST, and integrated GST. Apart from these, a compensation cess is being levied on certain luxury/ sin goods or services. Being value added tax it allows full set off of earlier stage taxed by way of inputax credit. The GST will be administered through the GST portal and the state and central government officers.
Customs duty is levied on imports and exports of goods. Customs duty is mainly collected on imports, though in very few cases export duty is also collected. The customs duty is leviable when the goods cross indian frontiers through sea, air or land borders.
been though the duties are levied as per customs act & tariff the imports and exports are regulated under the foreign trade policy.
Even though these levies are replaced by GST excise duty is still retained on few goods like petrol, diesel, crude, aviation fuel etc. Also certain legacy issues will be goermned by the old law. So these laws will be effective till the old assessments and siputes are resolvede finally.