Changing State Residency Before a Big Sale

How it works

States tax residents on all income and nonresidents only on income sourced to the state. A capital gain from selling an intangible, such as stock in a company or an LLC interest, is generally sourced to the seller's state of residence. So if you are a resident of Nevada, Texas, Florida, Washington (which has its own capital gains excise tax), or another state without an income tax on that gain when the sale happens, your old state generally cannot tax that gain.

The catch is in three places: what counts as a real change of residence, which gains stay sourced to the old state no matter where you live, and what happens to installment payments after you move.

Domicile and residency tests

California. A resident is anyone in California for other than a temporary or transitory purpose, or domiciled in California and outside it for a temporary or transitory purpose. The FTB looks at where you have your closest connections, and presumes residency for any year in which you spend more than nine months in the state (FTB Publication 1031). Factors include where your home is, where your spouse and children live, where you vote, hold a driver's license, bank, see doctors and keep professional and social ties.

New York. The state's nonresident audit guidelines list five primary factors for domicile: home, active business involvement, time, items "near and dear" and family connections. Separately, a person who keeps a permanent place of abode in New York and spends more than 183 days there is taxed as a statutory resident even if domiciled elsewhere.

Changing domicile requires both moving and intending to stay. The burden of proving a change is on the taxpayer. Keeping the old house, the old club memberships and the old doctors while claiming a new domicile is how cases are lost.

Gains your old state still taxes

• Real property. Gain on real estate is sourced to the state where the property sits. California taxes a nonresident's gain on California property, including on installment payments received years later (FTB Publication 1100, examples 2 and 7).
• Installment sales of stock made while a resident. FTB Publication 1100, example 8: a California resident sells stock on an installment basis, moves to Florida, and receives payments later. The capital gain stays taxable by California because the seller was a resident when the stock was sold. The interest on the note follows the seller's residence when received.
• New York accrual on moving out. New York requires a part-year resident moving out to accrue items that would be reportable under the accrual method at the time of the move, including gain elected to be reported on the installment basis (Form IT-203 instructions, special accruals).
• Business income from in-state operations. Gain that flows through to owners from a pass-through business with in-state operations, or a sale of assets of such a business, can be sourced or apportioned to that state regardless of where the owner lives. The structure of the sale (stock versus assets) matters.
• Retirement income is different. Federal law at 4 USC 114 bars states from taxing nonresidents on most retirement income, such as qualified plan and IRA distributions. It does not cover sale proceeds or installment notes.

Who it fits, and who it does not

Good fit: owners selling stock or membership interests in a company, who have a real reason and desire to live in the new state, and who can move fully before the sale is agreed.

Poor fit: sellers of in-state real estate, owners who plan to keep their main home and family life in the old state, and anyone whose deal is already signed or closing within weeks. A move made in a rush right before closing, followed by a return, is exactly the pattern auditors look for.

Worked example

Assumptions (site tax engine, 2026 law, labeled): married filing jointly, $200,000 of other ordinary income, a $5,000,000 long-term capital gain on the sale of company stock, all reported in 2026. California figures use the latest California table the engine carries.

The federal tax is identical. The entire difference, $631,339, is the state tax, and it disappears only if the sellers were genuinely Nevada residents when the stock was sold. If they sold on an installment note while still California residents and moved afterward, California would still tax the gain as payments arrive. If the asset were a California building, California would tax it either way.

IRS stance and audit risk

This is a state issue, not a federal one; the IRS does not care where you live. State audit risk is real. California and New York both run residency audits on high-income former residents, review travel records, phone and card data, home ownership and family ties, and can assess tax, interest and penalties years later. The safest pattern is a clean move well before the sale: sell or lease out the old home, move family and belongings, change licenses, registrations, voting, doctors and advisors, and keep a day-count log.

Costs and fees

The costs are personal and practical rather than fees: buying or renting a new home, moving, possibly selling the old home, part-year resident returns in the year of the move, and the cost of defending a residency audit if one comes. A residency attorney's review before the move is common for large sales.

How it compares with a Section 453 installment sale

A Section 453 installment sale spreads federal and state tax over the payment years. It does not by itself change which state taxes the gain. In California, the state of residence at the time of the sale controls gain on intangibles, so a sale on a note followed by a move does not shed California tax on the gain; only the interest follows you. Selling after a genuine move, with or without a note, is what changes the state answer. Sellers of in-state real estate get no state benefit from moving, but can still use an installment sale, a 1031 exchange or other tools to manage timing.

Frequently asked questions