Vacation rentals are common in ski areas in Colorado. A vacation rental is defined as a property that is rented at least 15 days and used for personal purposes. Certain expenses that are directly related to renting the property, such as advertising or agent's fees, can be fully deducted. Other expenses on such a vacation rental must be prorated according to the rental days compared to the personal days used. Any day you spend working on the rental property, such as cleaning or making repairs, is not considered a personal day, even if family members are using the property for recreation on the same day. However, any day rented to someone at a discount (as might be the case with friends or family) is considered a personal day. Also, if you use the property for personal purposes for more 14 days or 10% of the rented days, whichever is greater, you cannot take a loss on the rental activity.