Is it business travel or a vacation?
Everyone loves a vacation but when taxpayers attempt to deduct vacation travel expenses as business expenses, the IRS denies the deduction. The IRS Code requires a higher substantiation threshold for travel than for other business deductions. Therefore, it is important to understand the criteria for deducting business travel, especially when a trip is a combination of business activities and personal activities. It is important to have good business reasons for this travel and for the vacation to be incidental, especially as it relates to trips combining business and personal aspects.
In case of a spouse accompanying you, usually their expenses are non deductible unless you can show they are providing substantial business services directly related to your trip.