Stock Options and Remote Work: How Multi-State Taxes Actually Work
You moved from San Francisco to Austin. Your options were granted when you lived in California. You exercise them two years after the move. Do you owe California tax?
Yes — on a portion of the gain. This surprises almost everyone. Most people assume moving to a no-income-tax state eliminates state tax on future option exercises. It doesn't, because California (and New York) don't source stock option income to where you live when you exercise. They source it to where you worked while earning those options.
The result is a "trailing tax liability" that follows you across state lines and can cost six figures on a large exercise. Here's how it works, and what you can do about it.
The Workday Sourcing Rule: How States Divide Option Income
Most states that impose income tax follow a similar framework for taxing nonresidents on stock option income: the income is sourced based on the fraction of the option's "service period" that was worked in that state.
State-source income = Total option spread × (Workdays in that state during service period ÷ Total workdays during service period)
Service period = Grant date → Exercise date (for stock options; RSUs use grant to vesting)
Total workdays = All days worked across all states and countries during the service period
This formula was established in California under Revenue and Taxation Code §17014 and FTB Publication 1004.1 New York uses a similar approach under 20 NYCRR §154.6.2 Most states that source option income follow variants of this framework.
Worked Example: CA-to-TX Move
| Detail | Value |
|---|---|
| NQSO grant date | January 2022 (working in California) |
| Moved to Texas | January 2024 (2 years after grant) |
| Exercise date | January 2026 (2 years after move) |
| Service period total workdays | ~1,000 days (4 years) |
| CA workdays during service period | ~500 days (first 2 years) |
| CA workday fraction | 500 ÷ 1,000 = 50% |
| NQSO spread at exercise | $600,000 |
| CA-source income | $300,000 (50% × $600,000) |
| CA tax owed (12.3% marginal) | ~$36,900 — paid to California despite living in Texas |
| Texas state tax on same income | $0 (no TX income tax) |
The other 50% of the spread — attributable to your TX workdays — owes $0 in state tax. But the CA half doesn't disappear just because you moved. You must file a CA nonresident return (Form 540NR) in the year you exercise.
ISO vs. NQSO: The Sourcing Rules Differ
| Event | NQSO Treatment | ISO Treatment |
|---|---|---|
| At exercise | Spread = W-2 ordinary income. Sourced to states using workday fraction. Former CA/NY residents owe nonresident return. | Federally: AMT preference item only. California: still ordinary income at exercise (unique CA rule), sourced by workday fraction. NY: no state AMT — ISO exercise is not taxable at exercise for NY nonresidents. |
| Post-exercise appreciation (before sale) | Not taxable until sale | Not taxable until sale |
| Gain at sale (qualifying disposition) | Capital gain; sourced to state of residence at time of sale | For federal: gain above exercise FMV is LTCG, sourced to residence state at sale. CA nonconformity: CA may have already taxed the spread at exercise; remaining gain at ordinary rates, sourced to CA by workday fraction.1 |
| Disqualifying disposition | N/A | Spread becomes ordinary income (W-2). Same sourcing rules as NQSO apply for CA/NY purposes. |
New York's Convenience-of-Employer Rule
New York adds a second trap for remote workers: the convenience-of-employer rule. Under 20 NYCRR §132.18, if a New York employer's employee works remotely from outside New York for the employee's own convenience — not because the employer required it — New York taxes those remote-work days as New York workdays for sourcing purposes.2
What this means in practice:
- You work for a NYC company but live in Connecticut. The CT days you work remotely count as NY days under the convenience rule if your employer hasn't required you to be in CT.
- Your stock options sourced to NY will include a larger NY workday fraction than the raw geographic headcount would suggest.
- NYC city tax (up to 3.876%) applies to the NY-sourced income on top of the state rate.
The rule has been repeatedly upheld in New York courts and by the New York State Tax Appeals Tribunal. If you work remotely for a NY employer, you should assume NY taxes all those remote days unless you can document that your employer required the out-of-state arrangement.
How the Workday Fraction Changes as You Accumulate Post-Move Days
The fraction shrinks every year you stay in the no-income-tax state. Here's how that plays out for someone who was granted NQSOs in California and moves to Texas:
| Years in TX at Exercise | CA Workday Fraction | CA Tax on $500K Spread |
|---|---|---|
| Exercise before moving (still CA resident) | 100% | ~$66,500 |
| Move to TX, exercise 6 months later | ~80% | ~$53,200 |
| Move to TX, exercise 1 year later | ~67% | ~$44,600 |
| Move to TX, exercise 2 years later | ~50% | ~$33,250 |
| Move to TX, exercise 3 years later | ~40% | ~$26,600 |
| Move to TX, exercise 5+ years later (new grants) | Approaches 0% for post-move grants | Approaches $0 |
Example assumes all grant workdays were in California; 250 workdays/year; 12.3% CA marginal rate. Actual numbers depend on your specific grant date, move date, exercise date, and workday count.
The key insight: the fraction never reaches zero for options granted before the move. Time after the move dilutes it but never eliminates it. Options granted after the move, however, start a fresh service period with zero CA workdays — those are clean.
Planning Strategies
1. Exercise before you move (if options are already deep in-the-money)
Counterintuitively, exercising options while still a California resident can sometimes be smarter than waiting. CA taxes you on 100% of the spread regardless, but if you exercise early and hold for a qualifying disposition, the post-exercise appreciation is capital gain — not further sourced to CA. Compare: exercising in CA and holding for LTCG vs. exercising from TX and paying CA sourcing tax on the accrued spread plus the delayed timing cost.
2. Prioritize post-move grants
New grants issued after you establish residency in a no-income-tax state start with a zero CA workday fraction. If your company does annual refreshes, a grant received after your TX move date has no CA exposure at all. Delay exercises on pre-move grants; accelerate exercises on post-move grants when you have AMT or income headroom.
3. Document your move carefully
California is aggressive about challenging residency changes. Keep evidence: California driver's license surrender date, Texas DL issuance, home lease/purchase, voter registration transfer, employer HR record update, bank account changes. The FTB uses a "closest connections" test and will audit high-dollar relocators.
4. Track your workday count
Your CA workday fraction is based on documented workdays, not calendar days. Business travel back to California counts as CA workdays. Keep records of where you worked each day — calendar invites, hotel receipts, corporate badge swipes — for any year that includes options exercises.
5. Consider ISO early exercise + 83(b) before the move
For options with early-exercise rights and a low 409A, exercising before moving and filing an 83(b) election locks in a small ordinary-income event in CA, starts the QSBS clock, and converts all future appreciation into capital gain sourced to your post-move state. This is a high-complexity play that requires modeling — and a 30-day window — but it's available to employees who anticipate a move.
Which States Have the Highest Post-Move Risk
| Former Home State | Sourcing Rule | Top Rate on Sourced Income |
|---|---|---|
| California | Workday fraction (grant-to-exercise). ISO taxed as ordinary income at exercise. No LTCG preference. No QSBS exclusion. | 13.3% |
| New York + NYC | Workday fraction + convenience-of-employer rule. No state AMT on ISO exercises (unlike CA). Conforms to QSBS. | ~14.8% (state + NYC) |
| Oregon | Workday fraction. QSBS decoupled (OR SB 1507). Portland surcharges apply. | 9.9% + local |
| Minnesota | Workday fraction. State AMT on ISO exercises (6.75%). | 9.85% |
| New Jersey | Workday fraction per N.J.A.C. 18:35-5.3 (Aug 2024). | 10.75% |
| Connecticut | Compensation-ratio sourcing (Allen v. Commissioner). State AMT on ISOs. | 6.99% |
| Pennsylvania | Workday fraction. ISO taxed as ordinary income at exercise (same trap as CA). | 3.07% + Philly |
Common Mistakes
- Assuming moving eliminates all state tax. The workday fraction means a CA grant never fully escapes CA tax — it only dilutes over time.
- Not filing a nonresident return. California will issue an assessment if you have a CA workday fraction and don't file Form 540NR. The statute of limitations doesn't start until you file.
- Not tracking workday counts. If California audits you, they'll reconstruct workdays from your employer's records. Your own documented count will typically be lower.
- Business travel blurring the line. Traveling back to California for meetings during the service period adds CA workdays to your numerator. One week per quarter = ~10% of your annual workday count.
- Assuming 83(b) eliminates the problem for pre-move grants. An 83(b) on unvested stock affects vesting; it doesn't change the sourcing period for already-granted options with a prior strike price. The sourcing clock for grants already made still runs from grant date.
State guides referenced in this article
- California Stock Options Tax Guide — ISO ordinary income trap, no LTCG preference, no QSBS
- New York Stock Options Tax Guide — Convenience-of-employer rule, NYC city tax, QSBS conformity
- Texas Stock Options Tax Guide — No income tax, no capital gains tax, CA sourcing trap for relocators
- Washington State Stock Options Tax — Capital gains excise tax on ISO qualifying dispositions
- Oregon Stock Options Tax — 2026 QSBS decoupling (SB 1507)
- 83(b) Election Guide — Early exercise strategy for pre-move planning
- ISO Exercise Timing Guide — Qualifying vs disqualifying disposition framework
Model your multi-state exposure with a specialist
Calculating the exact workday fraction, modeling CA/NY nonresident returns, and timing exercises around your move requires someone who has done this dozens of times. Free match with a fee-only specialist.
Sources
- California Franchise Tax Board, FTB Publication 1004 — Stock Option Guidelines, rev. 2023. Explains workday-ratio sourcing for ISO and NQSO income for California nonresidents and part-year residents.
- New York State Department of Taxation and Finance, 20 NYCRR §154.6 and TSB-A-06(7)I — New York workday-fraction sourcing for stock options; convenience-of-employer rule application to remote workers.
- California Revenue and Taxation Code §17014 — California residency and source-income rules for nonresidents.
- New Jersey Division of Taxation, N.J.A.C. 18:35-5.3 (amended August 2024) — New Jersey workday-ratio allocation rule for deferred compensation and stock options.
Values and rules verified as of June 2026. State sourcing rules are subject to legislative and regulatory change; verify current rules with your tax advisor before exercising.