Relocating Mid-Year: How Part-Year Residency Taxes Your Salary

The audits on this site assume you live in one place for the whole year. Most relocations do not work that way. If you move from one state to another with income tax rules that differ — and especially if you move to or from a state with no income tax — the year of the move is taxed under two sets of rules, and the timing of the move decides how much of your salary each state sees. This guide explains the mechanism in general terms; it is not tax advice, and the year of a move is a good year to have a professional prepare the return.

Part-year residency, in principle

Every state with an income tax taxes its residents on all their income and non-residents on income sourced in the state. In the year you move, you are a part-year resident of both: the old state taxes what you earned while resident there (and anything sourced there afterward), and the new state taxes what you earned after you arrived. You file a part-year return in each. In principle, no dollar of wages is taxed by both — each dollar is allocated to one state, usually by the date it was earned.

A worked example

A $120,000 earner moves from California to Texas on 1 July. California’s full-year tax at that salary would be $8,627 (state tax plus SDI). For the first half of the year, roughly $60,000 of wages is California-sourced. Because California’s brackets are progressive, the tax on $60,000 of a part-year return is not simply half of $8,627 — California computes tax on your full-year income to find the rate, then applies that rate to the California portion, so the bill on the first half comes out close to half the full-year figure, around $4,300. Texas taxes nothing on the second half. The year’s state bill is about $4,300 instead of $8,627 — or instead of $0, depending on which way you were expecting it to go.

Move on 1 October instead and California’s share is roughly three-quarters. Move on 1 February and it is a twelfth. The date is the lever.

Where it gets complicated

Remote work for the old employer. If you keep working for a California employer after moving to Texas, California generally does not tax wages for work physically performed in Texas. New York is different: under its “convenience of the employer” rule, a New York employer’s remote worker in another state can remain taxable by New York on those wages unless the remote arrangement is for the employer’s necessity. Pennsylvania, Delaware, Nebraska and a few others have versions of the same rule. Check the rule in the state you are leaving before assuming your income becomes tax-free.

Domicile vs. residence. States distinguish where you live from where your permanent home is. A high-tax state can continue to treat you as a resident if you keep a home, a driver’s licence, a voter registration or a family there. California and New York both audit high earners who move out; the practical advice is to change every registration you can within weeks of the move and keep the evidence.

Withholding lags. Your employer withholds for the state on file. Tell payroll the day you move, or you will have too much withheld for the old state and too little for the new — which is fixable at filing but not pleasant.

Signing bonuses and equity. Some states source a bonus or vested stock to where you were resident when it was granted, not when it was paid. This is the item most likely to surprise people who move after accepting an offer.

Estimating the year of the move

Open the audit for your salary in each state. Take the state-plus-payroll line from each, weight it by the fraction of the year you will spend there, and add them. It is an approximation — progressive states use the rate-on-full-income method described above, and local taxes are prorated the same way — but it is within a few hundred dollars for most salaries and is a far better planning number than either full-year figure alone.

Then, in the year after the move, the audit for your new state is simply the answer.