Time Spent In Home
If you own and live in only one home, that home is your primary residence. If you own and live in more than one home, the IRS judges your primary residence by which home you spend more time in. For example, if you live in one home for eight months out of the year and the other home for four months out of the year, the home that you spend eight months in is your primary residence.
If you spend equal amounts of time in more than one residence, the IRS may examine your address on your government-issued documents to determine which address is your primary address. For example, if your driver's license lists the address of one of your residences, the IRS is more likely to consider that your primary residence, especially if you use this address for federal and state taxes.
The IRS also examines where you have built a life for yourself. For example, if you belong to a religious organization and participate in social activities in the city where one of the residences is located, the IRS is more likely to consider this your primary residence than a residence that is farther away from your social activities. In addition, the IRS examines where you have opened your bank account, where you go to the doctor and other evidence suggesting that you have built your life somewhere.
The IRS makes its determination based on the whole picture, not just one isolated fact. For example, if you have built your life in a community and spend the majority of your time in a residence in that community, the IRS is unlikely to determine that your primary residence is elsewhere just because your driver's license has this alternate address. Similarly, if you have one address on all your government documents but spend almost all your time at the other residence, the IRS is likely to consider the second residence as your primary residence.