California, like other higher-tax states, has residency auditors whose specialty is asserting that affluent people who have left the state are still legal residents and thus are subject to its taxes. The audits can be stunningly thorough, looking at everything from the doctors you visit to where your artwork and other valuable possessions are stored.
If audited, you would need to prove that you have a fixed, permanent residence elsewhere and that it’s truly your home. And yes, it’s up to the taxpayer to prove this — there’s no presumption of innocence in tax audits, says tax attorney Mark Klein, chairman of Hodgson Russ LLP in New York City. (New York is another state with notoriously hard-nosed residency auditors.)
Just leaving the state for six months and registering to vote elsewhere typically won’t be enough. You likely would need to spend substantially more time in your new “home” state than in California. Klein, who recently taught a session on establishing residency at the AICPA’s annual ENGAGE conference, tells his clients to spend at least two months in the new place for every month they spend in the old one.