Before the introduction of the Goods and Services Tax (GST) in India, the constitutional framework of indirect taxation was governed primarily by the provisions of the Constitution of India and various legislative enactments at the central and state levels. The key features of the constitutional framework of indirect taxation before GST are as follows:

1. Distribution of Legislative Powers: The Constitution of India provided for a dual system of taxation, whereby both the central and state governments had the authority to levy and collect taxes on certain goods and services. The distribution of legislative powers between the central and state governments was delineated under Articles 246 and 265 of the Constitution.
2. Union List and State List: The Seventh Schedule of the Constitution divided the subjects of legislation into three lists: the Union List, the State List, and the Concurrent List. The Union List contained subjects on which only the central government could legislate, including taxes such as customs duties, central excise duties, and service tax. The State List contained subjects on which only the state governments could legislate, including taxes such as sales tax, value-added tax (VAT), and entertainment tax.
3. Central Excise Duties: The central government had the exclusive authority to levy and collect excise duties on the manufacture of goods in India under Entry 84 of the Union List. Central excise duties were imposed on the production or manufacture of goods within the country and were governed by the Central Excise Act, 1944.
4. Customs Duties: The central government had the power to levy and collect customs duties on the import and export of goods under Entry 83 of the Union List. Customs duties were imposed on goods crossing the borders of India and were governed by the Customs Act, 1962.
5. Sales Tax and VAT: The state governments had the authority to levy and collect taxes on the sale of goods within their respective territories under Entry 54 of the State List. Initially, sales tax was levied as a single-stage tax at the point of sale, but over time, many states transitioned to a value-added tax (VAT) system, which taxed the value added at each stage of production and distribution.
6. Service Tax: The central government had the authority to levy and collect service tax on specified services under Entry 92C of the Union List. Service tax was introduced in India in 1994 and initially applied to a limited number of services. Over time, the scope of taxable services expanded, and service tax became a significant source of revenue for the central government.
7. Inter-State Trade and Commerce: The Constitution provided for the regulation of inter-state trade and commerce under Article 286, which restricted the power of states to levy taxes on the sale or purchase of goods in the course of inter-state trade or commerce. However, states could impose taxes on goods imported from other states subject to certain restrictions.
8. Legislative Framework: The central and state governments enacted various legislations to levy and collect indirect taxes, including the Central Excise Act, 1944, the Customs Act, 1962, the Central Sales Tax Act, 1956, and state-specific sales tax laws.

The constitutional framework of indirect taxation before the introduction of GST was characterized by a complex and fragmented tax regime with multiple taxes levied by both the central and state governments. The introduction of GST aimed to streamline the indirect tax system by replacing multiple taxes with a single, comprehensive tax, thereby facilitating ease of compliance, reducing tax cascading, and promoting uniformity and efficiency in the taxation of goods and services across the country.