New Delhi, Sept. 23 -- Of the three great taxes India that collects, customs is an exception. Income arises today, tax on it is deposited monthly and returned annually. As for tax on consumption, a supply is made today, and goods can travel the country on an e-way bill without goods and services tax being paid, since GST is due only next month.

Import a consignment into India, however, and the goods will not be cleared until customs duty is paid. It could be the same taxpayer and the same government, but the country's tax system operates on two opposite theories of trust, separated by a shoreline.

An exception to such stiff clearance already exists. Since 2016, under a facility drawn from the World Customs Organization, authorized econo...