The heart of Google's (GOOG) international operations is a silvery glass office building in central Dublin, a block from the city's Grand Canal. In 2009 the office, which houses roughly 2,000 Google employees, was credited with 88 percent of the search juggernaut's $12.5 billion in sales outside the U.S. Most of the profits, however, went to the tax haven of Bermuda.
To reduce its overseas tax bill, Google uses a complicated legal structure that has saved it $3.1 billion since 2007 and boosted last year's overall earnings by 26 percent. While many multinationals use similar structures, Google has managed to lower its overseas tax rate more than its peers in the technology sector. Its rate since 2007 has been 2.4 percent.