The California FTB Residency Audit: How a Founder Who Moved to Austin Defends a §17014 Domicile Challenge on $4M of RSUs.

A software founder spends eleven years building a company in San Francisco, then moves to Austin in early 2025, a few months before a tender offer turns roughly $4 million of restricted stock units into cash. She files a part-year California return, reports the move, and assumes the rest of the gain is now Texas income, where there is no state income tax. Fourteen months later an FTB 4600 notice lands in the mailbox, and the California FTB residency audit begins. The Franchise Tax Board is not asking whether she bought a house in Texas. It is asking whether, under the law, she ever stopped being a California resident at all. With no long-term capital gains preference at the state level, California's 13.3% rate applies to that RSU income in full if the answer is no.

California Revenue and Taxation Code §17014 defines a resident two ways, and a founder who moves can be caught by either. The first prong is anyone in California for other than a temporary or transitory purpose. The second, the one that snares movers, is anyone domiciled in California who is outside the state only for a temporary or transitory purpose. Domicile is your true, fixed, permanent home, the place you intend to return to whenever you are away, and the regulations are blunt that you can have only one at a time. You do not change domicile by buying a plane ticket. You change it by abandoning California as your home and establishing a new permanent home elsewhere, in fact and in intent, and the burden of proving you did so falls on you, not the FTB.

That burden is the whole game. The theory running through §§17014 through 17016 is that you are a resident of the state with which you have the closest connection during the tax year. A part-year return tells the FTB you claim the connection shifted on a specific date. The audit tests whether your life actually moved, or whether you kept California as home and parked a second address in Texas for the year of the exit.

A residency audit usually opens with an FTB 4600 demand or a narrowed residency letter, followed by an information document request and, often, an interview or sworn affidavit. The examiner then scores your year against the factors from the Appeal of Stephen D. Bragg, 2003-SBE-002, the case every California residency dispute still cites. The Office of Tax Appeals groups the Bragg factors into three buckets: registrations and filings with a state or agency, personal and professional associations, and physical presence and property. In practice the examiner is counting days, locating your spouse and children, finding where your driver's license and vehicle registrations sit, where you are registered to vote, where your doctors and dentists and accountants are, where your bank and brokerage accounts are held, and where you actually slept on the night of the liquidity event.

No single factor controls, but recent decisions make clear that physical presence carries the most weight. In the 2025 Appeal of Q. Tran and R. Medina, OTA Case No. 21088364, the Office of Tax Appeals rejected a claimed move to Nevada because the taxpayers' own day count showed far more days in California than in the new state, holding that acts and physical presence matter more than stated intent and paperwork. For a founder, the lesson is direct. Signing a Texas lease the week before the tender offer while your kids finish the school year in Palo Alto and your car still wears California plates is not a change of domicile. It is a paperwork trail the examiner will pick apart.

Residents are taxed on all income from every source under §17041, so if the FTB wins the residency question, the entire $4 million is California income. If you prevail as a nonresident, California reaches only the portion sourced to work you performed in the state. The gap between those two outcomes is the reason these audits exist.

Winning the residency fight does not make the RSUs tax-free in California. Compensation income is California-source to the extent the services that earned it were performed in California, no matter when the cash arrives. For RSUs the measuring period is grant to vest, and 18 CCR §17951-5, summarized in FTB Publication 1004, sources income by the ratio of California working days to total working days across that window. A grant made three years before the founder left, vesting after the move, is still mostly California income because most of the work that earned it happened in California. That allocation math, and the trap of assuming a move zeroes it out, is the same one I walk through in California's RSU tax after you move out of state. The move limits the exposure on future workdays. It does not erase the years already vested in California.

People hear there is a bright-line rule and reach for it. There is one, but it almost never fits this fact pattern. R&TC §17014(d) treats someone domiciled in California as a nonresident if they are absent under an employment-related contract for an uninterrupted period of at least 546 consecutive days, roughly 18 months. The safe harbor is fragile: return visits to California cannot exceed 45 days in a taxable year, intangible income such as interest, dividends, and capital gains over $200,000 in any year blows it, and it is unavailable if the principal purpose of the absence is avoiding tax. A founder who moves to start a new company, or simply to live in Austin, is not absent under an employment-related contract and is not within the safe harbor at all. For most movers the only real defense is the closest-connection analysis, won on facts, not the 546-day count.

So the defense is built before the exit, not after the notice. Move the family, change the driver's license and voter registration, re-register the cars, switch doctors and banks, and spend real, documented days in Texas in the year of the liquidity event, ideally before the income is recognized. Keep a contemporaneous day log, because the examiner will reconstruct yours from credit card swipes and cell tower data if you do not bring your own. A residency position decided by a calendar and a paper trail is one you want to have set deliberately, the same way you would plan around Washington's 7% capital gains tax on an RSU sale before clicking sell, rather than explaining it to an auditor two years later.