A movie about a depressed father, a patient mother, an understanding daughter, living in the desert ( isolated) who get visited by a tenacious tax man. The daughter orders her father a boat for his birthday with a credit card she got by applying through the mail.

If this is a relatively recent movie, I think you are talking about Off the Map. Please see this link.Off the Map (2003) (http://imdb.com/title/tt0332285/)