Omar moved from San Francisco to Austin in March for a remote role at a startup. The offer was strong, $115,000, fully remote, no state income tax in Texas. He did the math: California's top marginal rate was 9.3% on his income. Moving to Texas meant keeping roughly $8,000 more per year. The decision felt obvious.
What Omar didn't plan for was the overlap.
His San Francisco lease ran through May. He moved to Austin in March, started the new job immediately, but didn't update his address with HR until mid-April. For three months (January through March) he was earning income while still technically a California resident.
California taxes income earned while you're a resident of the state, regardless of where your employer is located. Omar was a California resident for the first quarter. He owed California income tax on that quarter's earnings, roughly $28,750 in salary, taxed at his effective state rate. The bill came to about $2,100.
But it got worse. Because he didn't update his W-4 with his new employer until April, his employer wasn't withholding California taxes during Q1. Nobody was. The $2,100 was owed in full at filing time, plus an underpayment estimate penalty of about $85.
Then there was the partial-year residency filing. Omar had to file a California part-year resident return (Form 540NR) and a Texas return (Texas has no state income tax, so there's no form to file, but the California form required him to document his Texas income to calculate the California portion correctly). The California form was confusing enough that he paid a CPA $450 to handle it.
Total cost of the three-month overlap: roughly $2,100 in California state tax, $85 in penalties, and $450 in CPA fees. That's over $2,600 in unexpected costs, plus the $1,600 he spent on rent for a San Francisco apartment he wasn't living in.
How States Define Residency
Every state has its own rules, but most use two tests:
Domicile: Where you intend to make your permanent home. Changing your domicile usually requires several concrete steps, getting a driver's license, registering to vote, signing a lease or buying property in the new state.
Statutory residency: Some states (including California and New York) consider you a statutory resident if you maintain a "permanent place of abode" in the state for more than a certain number of days, typically 183. Omar's San Francisco apartment, even empty, counted.
The safest approach: end your lease, change your driver's license, register to vote, and update your address with your employer all before or on the day you start earning income in the new state. The cleaner the break, the simpler the tax situation.
The Paycheck Difference
Use our Paycheck Calculator to compare your take-home pay in different states. On a $115,000 salary, moving from California to Texas increases annual take-home by roughly $7,500–$8,500 depending on filing status and deductions. That's real money, but only if you make a clean transition.
Omar's advice: "End your lease before you start the new job. I thought keeping the apartment 'just in case' was a safety net. It was a $4,200 lesson in state tax residency rules."
He's been in Austin for over a year now. His paychecks are bigger, his cost of living is lower, and his California tax liability is exactly zero. The move was worth it. The overlap wasn't.