Deduct costs associated with travel outside the United States. Even if you did not spend your entire time on business, you can deduct the entire cost of your travel outside the United States--if you meet any of the following three exceptions:

  • You were outside the United States no more than one week (7 consecutive days).
  • You were outside the United States and less than 25 percent of the time was spent on non-business (personal) travel.
  • You can establish that a personal vacation was not a major consideration, even if you have substantial control over arranging the travel.

Source: "Travel-Related Tax Deductions"