The Federal Law That Could Topple Maryland’s Ad Tax, Explained

The Internet Tax Freedom Act, which bars discriminatory taxes on electronic commerce, may be the most important and least understood federal law affecting state and local taxes.

Much of the confusion can be attributed to Congress never designating an agency to interpret the 1998 law. Similarly, very little case law—and little of precedential consequence—has emerged over the last 26 years to define the limits of the federal preemption statute.

Against this backdrop, ITFA’s capacity to limit the taxing authorities of states, cities, and counties could gain some muscle before the end of the year if Apple, Google, ...