multiple residences in different states really raises the question of domicile. you can have multiple residences, reside in multiple states but can have only one domicile. domicile is important for income tax purposes and estate tax purposes and possibly other purposes.
Many states look to a person’s domicile to determine residency. An individual generally has only one domicile, which is the place considered the true home, the place where the individual intends to return to when away. Although an individual may have more than one residence, (i.e. a place where the individual is present from time to time) it is critical that he/she solidify in the eyes of the state one domicile or true home for estate tax purposes. Due to differences in state rules, an individual may be held to have more than one domicile or true home (Hill v. Martin, 296 U.S. 393(1935)). The unfortunate consequence of such a situation is that two states can constitutionally tax the estate of the same individual as a domiciliary, so long as all the death taxes do not exceed the estate’s total value.
Howard Hughes is probably the most famous name where his estate had to deal with domicile. He didn't establish it in either California or Nevada where he split his time. Both states litigated the issue. It cost his estate millions in legal fees because representation was needed in both states. It took years to settle.
