BANGALORE, India — Lawmakers cleared the way on Wednesday for India to forge a single economic zone from its thicket of overlapping federal and state taxes, the most important economic measure since India opened its markets in 1991.

Potentially one of the most dynamic economies in the developing world, India is hampered by a bewildering array of state-by-state tax codes that discourage doing business across state borders.

The Goods and Services Tax is widely viewed as a breakthrough that will allow the authorities to confront the problem, eventually creating a more unified economy that will allow businesses to expand nationwide far more easily.

“This is long overdue but hugely consequential for the ease of doing business, and for demonstrating to the outside world that India is dragging its economy into the 21st century,” said Milan Vaishnav, a senior associate in the South Asia program at the Carnegie Endowment for International Peace.