Indians hit stores in shopping frenzy ahead of GST

India has debated such a tax for over a decade. While economists mostly agree a single, nationwide tax will streamline business, there are concerns about how an economy as unwieldy as India's will transition to a system that involves filing monthly tax returns online.

The government published lists last month of how almost every item, from toothbrushes to automobiles, will be taxed at rates of 5 percent, 12 percent, 18 percent or 28 percent.

Businesses were ordered in January to adopt or upgrade cash registers and computers so they could comply with the changes before they took effect.