When Josh Beckett pitches for the Red Sox at Yankee Stadium, New York collects income tax on the portion of his salary that he earned in New York State.
But what about a Boston Scientific sales representative who comes to New York to pitch medical products to a new client? New York has decided it wants a slice of that paycheck, too.
Anyone who crosses a state border for work — to make a sales call, say, or meet with a client or do a road show on Wall Street — probably owes income taxes in that state.
If you live in Boston but spend one out of 250 workdays this year in New York, you owe New York income taxes on 1/250th of your salary. And vice versa if you are a New Yorker visiting Boston — or Anywheresville, for that matter — for business.
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In some cases auditors check to see if, say, an employee who was reimbursed for airfare to California also had California income taxes withheld from his paycheck. If not, the company can be fined.
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http://www.nytimes.com/2010/03/22/business/22tax.html?th&emc=th
This should really cut down on business travel!