The American rental firm Vrbo (taken over by HomeAway.com) is an online rental agent (similar to AirBnB). As they are US based they are required to identify foreign owners and withhold the appropriate tax if a US tax identification number has not been provided to them. When you own US rental property, you are required to file Federal tax returns each year for the income earned (on Form 1040NR). Depending on the state the property is based in, you may also have to file a State