A tax nightmare could face big law firms and other multistate service providers if the U.S. Supreme Court this term requires retailers to collect sales taxes in states where the business has no physical presence.

The justices will hear arguments on April 17 in the case South Dakota v. Wayfair. South Dakota and its supporters urge the high court to overrule its 1992 decision that said only retailers with a physical presence within a state can be required to collect that state’s sales tax. Numerous state and local governments say a ruling for South Dakota could mean billions of additional dollars for cash-hungry government budgets.