California Stock Option Source Rules: How CA Taxes Options for Nonresidents and Movers
The Basic Rule: Service Sourcing for Equity Compensation
California Revenue and Taxation Code §17041 imposes income tax on California residents on all income from all sources, and on nonresidents on California-source income only. The implementing regulation for compensatory equity is found at 18 CCR §17951-5, which the Franchise Tax Board summarizes in FTB Publication 1004 (Stock Option Guidelines). The principle: compensation income is California-source to the extent the underlying services were performed in California, regardless of when payment is received.
For stock options, the relevant ‘compensation period’ is the grant-to-exercise window for NQSOs and ISOs, and the offering period for ESPPs. For RSUs (covered in a separate post), it’s grant-to-vest. The differences matter — they create different planning levers.
California’s position: an employee earns the option by working through the vesting period. By the time the option is exercised, the spread (FMV at exercise minus strike price) is realized compensation, and the portion of that compensation attributable to California-service days is taxable to California even if the employee is a nonresident at exercise.
Workday allocation formula for NQSOs: (CA workdays during grant-to-exercise period / total workdays during grant-to-exercise period) × total exercise spread = California-source compensation income.
This is service-based allocation. It doesn’t matter where the company is headquartered, where the broker is, or where the stock is traded. What matters: where the employee performed services during the relevant period.
The FTB has consistently applied this rule in audit and on appeal. Appeal of Charles G. Berry (2019) and similar cases at the Office of Tax Appeals confirmed that grant-to-exercise sourcing applies even when the taxpayer has been out of California for years before exercising.
NQSO Sourcing: The Grant-to-Exercise Window
Non-qualified stock options are the cleanest case. At exercise, the spread between the fair market value of the underlying shares and the strike price is ordinary compensation income reported on Form W-2 (or 1099-MISC if you’re a contractor). The employer typically withholds federal and state income tax at exercise.
California sourcing methodology for NQSOs: the entire grant-to-exercise period is the relevant ‘earning period.’ Even if vesting completed years before exercise, the period from grant date through the date of exercise is the window over which California measures service location.
Example: NQSO granted January 2020 with 4-year graded vesting (25%/year). Strike $5/share. 10,000 options total. You work in San Francisco 2020-2023, move to Austin January 2024, continue working remotely for the company through 2026, and exercise all 10,000 options in December 2027 when FMV is $80/share.
Spread at exercise: 10,000 × ($80 – $5) = $750,000 ordinary income.
Grant-to-exercise period: January 2020 to December 2027 = 8 years = ~2,016 workdays.
CA workdays during grant-to-exercise: 2020-2023 = ~1,008.
CA allocation: 1,008 / 2,016 = 50%.
California-source compensation: 50% × $750,000 = $375,000.
CA tax (at ~13.3% top rate on additional income): approximately $50,000.
Key insight: by delaying exercise from 2024 (right after moving) to 2027 (4 years later), you extended the grant-to-exercise window from 4 years to 8 years. CA workdays stayed at ~1,008, but total workdays doubled — so the CA allocation dropped from ~100% (had you exercised right at move) to 50%. The longer you defer exercise (while continuing to work outside California), the more diluted the CA-source portion becomes.
Practical limit: most NQSOs expire 10 years from grant. You can defer exercise, but not indefinitely. The §83 tax cost of exercising late also rises with the spread, so deferral isn’t free.
Withholding mechanics: the employer is required to withhold California income tax on the CA-source portion of the exercise income. Some employers default to withholding on the full spread (over-withholding) and let the employee claim the refund on a California 540NR. Others get the allocation right at payroll if the employee has clearly documented their move. If you’ve moved out of California, send your employer a written notice with your move date and updated address, and ask payroll how they’ll allocate.
ISO Sourcing: When Exercise Doesn't Create Regular Income
Incentive Stock Options work differently because the federal tax treatment is different. At exercise of an ISO, the spread is not ordinary income for regular tax purposes — it’s an AMT preference item under IRC §56(b)(3). The regular-tax compensation event happens later, at sale: if you hold the shares for 1 year post-exercise and 2 years post-grant (the §422 holding period), the entire gain at sale is long-term capital gain. If you sell earlier, the spread at exercise becomes ordinary income (a disqualifying disposition).
California conforms to most of the ISO federal treatment but with twists. For regular CA income tax: ISO exercise itself is not a CA-source event. ISO compensation (when realized via disqualifying disposition or via the regular-tax compensation event) is sourced to California based on grant-to-exercise workdays — same methodology as NQSOs.
AMT impact: California has its own AMT system under R&TC §17062. For California AMT purposes, the spread at ISO exercise is a preference item, but only the California-source portion. If you’re a nonresident at exercise and only 30% of your grant-to-exercise workdays were in California, only 30% of the spread is a CA AMT preference item.
The mover’s AMT trap: if you exercised ISOs while a CA resident and held the shares (avoiding disqualifying disposition), you owed CA AMT on the full spread. If you then moved out of California and sold the shares in a later year as a nonresident, the long-term capital gain at sale is generally not CA-source (CA doesn’t tax intangible gain for nonresidents). But the CA AMT credit you generated from the earlier exercise sits on your California return for years to come, often unusable because you have no CA tax to offset.
Example: 5,000 ISO shares exercised in 2022 while a CA resident at $50 spread = $250,000 AMT preference. CA AMT: ~7% × $250,000 = $17,500 paid in 2022. You move to Texas in 2023 and sell the shares in 2025 as a TX resident. The gain at sale is federally long-term capital gain (qualifying disposition). For CA: the gain at sale is not CA-source for a nonresident. You have $17,500 of CA AMT credit sitting on your CA Form 3510, but no CA regular tax to absorb it — so the credit may never be used.
Planning point: don’t exercise ISOs and hold while a California resident if you’re planning to move within the next 1-2 years. Either exercise-and-sell same year (disqualifying disposition, taxed as ordinary income but no AMT trap), or wait until after you’ve moved to exercise so the AMT preference is sourced as nonresident.
Disqualifying Dispositions and the Source Mechanics
If you sell ISO shares before the §422 holding period (1 year post-exercise, 2 years post-grant), it’s a disqualifying disposition. The federal treatment: the lesser of (a) the spread at exercise or (b) the gain at sale is ordinary compensation income on your W-2. Any additional gain is short-term or long-term capital gain depending on holding period.
California sourcing for the disqualifying disposition compensation portion: same as NQSO — grant-to-exercise workday allocation. The ordinary income component is treated like NQSO income for source purposes.
Capital gain on disqualifying disposition: the capital gain portion is intangible income. For California nonresidents, intangible capital gain is not California-source under R&TC §17952 (with limited exceptions for installment sales of California real or business property). So if you exercise ISOs while in California, hold for 8 months, move to Florida, and sell at month 10 — you have a disqualifying disposition. The ordinary income component is sourced to CA based on grant-to-exercise (likely high CA percentage because you just left). The capital gain component (if any) is not CA-source.
Tactical question: should you do a disqualifying disposition deliberately to convert ISO treatment to NQSO treatment? Sometimes yes — especially if (a) the AMT hit on holding would be punishing or (b) you’re about to lose ISO status anyway by leaving the company. IRS Publication 525 covers the federal ISO disqualifying disposition rules in detail.
ESPP Income for Nonresidents
Employee Stock Purchase Plans qualifying under IRC §423 have their own quirks. Under a typical 6-month or 24-month offering period, the employee contributes after-tax dollars through payroll and at the end of the offering period buys company stock at the lower of the offering-period beginning price or end price, often with a 15% discount.
Two tax events: (1) the qualifying discount that exceeds the actual discount creates ordinary compensation income at sale of the ESPP shares (assuming qualifying disposition — 2 years post-offering and 1 year post-purchase). (2) The remaining gain at sale is capital gain.
California sourcing for the compensation element: based on workdays during the offering period (not the grant period for stock options).
Example: 24-month ESPP offering started January 2023. You work in San Francisco 2023, move to Seattle January 2024. Offering ends December 2024 and you buy shares at $42 (15% discount from $50 FMV at end). You sell in 2026 at $80.
Compensation element at sale: 15% × $50 = $7.50/share = ordinary income. Offering period: 24 months. CA workdays during offering period: 12 months = 50%. CA-source compensation: 50% × ($7.50 × shares).
Capital gain: $80 sale – $50 FMV at purchase = $30/share. Not CA-source for nonresident.
The ESPP compensation amount typically shows up on Form W-2 in the year of sale (the company tracks it and reports it as wages even though it’s tied to a sale in a different year). California gets allocated based on offering-period workdays.
Disqualifying dispositions of ESPP shares (sale before holding period satisfied): the entire spread at purchase becomes ordinary compensation income, and California sourcing follows the offering period.
Workday Calculation: What Actually Counts
The FTB’s workday allocation requires you to count California workdays during the relevant period. ‘Workday’ generally means a day the employee performed services for the employer. Vacation days, holidays, weekends — these are excluded from total workdays in the denominator under FTB Pub 1004.
Standard year: ~252 workdays (5 days × 52 weeks, minus 8 holidays).
Days worked in California: count days physically present in California performing employee services. A business trip to a Los Angeles client meeting counts as a CA workday even if you’re a Texas resident.
Days worked outside California: count days physically present outside California performing services. Working from your Texas home for the SF employer is a TX workday, not a CA workday.
The FTB will accept calendar-based estimates if you don’t have detailed records, but the burden falls on the taxpayer to substantiate. Calendar entries, travel records, employer payroll records showing work location — all useful.
Common errors:
– Treating residency days as workdays: if you were a CA resident but on vacation in Italy for 2 weeks, those 14 days are not CA workdays. They’re vacation days excluded from both numerator and denominator.
– Treating remote work as CA workdays just because the employer is in CA: California does not have a ‘convenience of employer’ rule. If you physically worked from your home in Texas for a California employer, those are Texas workdays. (Contrast with New York’s convenience rule, which treats remote work for NY employers as NY workdays unless the work is for the employer’s necessity.)
– Counting only paid workdays: include all service days, whether paid or unpaid (e.g., unpaid PTO if you worked through it).
Recordkeeping recommendation: from the moment you move, keep a calendar of CA presence and a log of business trips. The FTB will request this on audit and reconstructing 5 years later is a nightmare.
The 4-Year Lookback and FTB Audit Triggers
California’s general statute of limitations on income tax assessment is 4 years from the return due date under R&TC §19057. The FTB can audit your 540NR return for 4 years. For substantial omissions of income (over 25% understatement), the period extends to 6 years. For fraud, no statute applies.
What triggers an FTB stock option audit? Common patterns:
– Large W-2 wages reported in years after you’ve moved, with no California allocation shown on Form 540NR.
– A discrepancy between the W-2 issued by a California employer (showing some CA wages from prior years’ work that’s now being paid out via vesting/exercise) and what’s reported on 540NR.
– A move-out year (final 540 or first 540NR) showing significant out-of-state allocation of equity compensation income that the FTB doesn’t believe.
– An IRS information-sharing report showing equity compensation income that wasn’t included on your CA nonresident return.
The FTB receives copies of W-2s issued by California-located employers regardless of the employee’s residence. If the W-2 shows CA wages, the FTB expects to see those wages on your CA return — either as a resident (Form 540) or as a nonresident with allocated CA-source compensation (Form 540NR).
Recent enforcement: the FTB has dedicated examiners focusing on stock-based compensation for departing employees in tech hubs. Common assessment: $50K-$300K of additional CA tax with penalties and interest on multi-year unreported equity compensation. The California Office of Tax Appeals has a steady stream of equity-compensation appeal cases.
Audit defense: documentation of move date, ongoing work location records, and the calculation methodology used to allocate. The FTB will accept a reasonable allocation; what they won’t accept is no allocation at all.
Planning Moves for Departing California Employees
Several planning techniques are available depending on the option type and timing:
1. Exercise NQSOs BEFORE moving, while still CA resident. This locks the source as 100% CA (which you can’t avoid anyway since you’re a resident), but it removes future uncertainty. You’ll pay CA tax on the full spread at the resident rate, but you won’t have an open lookback exposure on future NQSO exercises.
2. Defer NQSO exercise as long as possible AFTER moving. The longer the grant-to-exercise window stretches with out-of-state workdays, the more diluted the CA-source allocation becomes. As shown earlier, deferring from 2024 to 2027 cut a 100% CA allocation to 50%.
3. Exercise ISOs same-day as sale (disqualifying disposition) if move is imminent. This converts ISO to NQSO-like treatment, sources based on grant-to-exercise, and avoids the AMT-credit trap of holding through a move.
4. Skip employer’s California allocation defaults. Many large California employers default-allocate 100% of equity comp to California for prior years’ grants regardless of current residence. The employee can override this on the personal return (Form 540NR) by using the workday allocation, but it requires backup.
5. Don’t keep working remotely for a California employer if you’re trying to minimize CA exposure on future grants. Remote work for a CA employer is not CA-source under California’s rules (unlike New York), but if the company has a California office and treats you as performing services there, the line can blur. Get clarity from HR.
6. Coordinate with state of new residence. Texas, Florida, Nevada, Washington, Wyoming, Tennessee — no state income tax, so the non-CA portion of stock comp income is fully tax-free. New residency in Oregon, New York, Massachusetts, or other high-tax states means the non-CA portion is still subject to your new state’s income tax. The post-move state may also have its own equity comp source rules.
7. Track the move date precisely. Domicile change requires both physical relocation and intent to remain. The FTB will challenge a ‘soft’ move where you kept a California home, voter registration, kids in CA schools, etc. FTB residency audits are common for departing high earners.
Treatment of Restricted Stock vs. Options
Don’t conflate restricted stock awards (RSAs) with stock options. RSAs are actual shares granted up-front but subject to forfeiture. The two diverge sharply on tax treatment.
Section 83(b) election: within 30 days of receiving restricted stock, you can elect under IRC §83(b) to be taxed immediately on the value of the shares at grant. If FMV at grant equals the price paid, the §83(b) creates zero current income — but starts the capital gain clock and locks the source as wherever you were at grant.
California sourcing for §83(b) elections: the income is sourced based on where services were performed up to grant. For a grant on day one of employment, this is typically 100% CA-source if granted while a CA employee.
Without §83(b): the restricted stock is taxed at vesting like RSUs. California sources based on grant-to-vest workdays (not grant-to-exercise).
RSUs (no §83(b) available): always sourced grant-to-vest. Covered in our companion post on California RSU rules.
PSUs (Performance Stock Units): if vesting depends on performance milestones, the relevant period is grant-to-vest (the date the performance condition is satisfied). For source purposes, the workday allocation runs from grant to performance vest date.
The lesson: the type of equity comp drives the source rule. Don’t apply RSU rules to ISOs or vice versa. Don’t apply §83(b) election thinking to RSUs (you can’t make the election on RSUs because they aren’t stock until vesting).
Multi-State Allocation When You Worked Outside California
If during the grant-to-exercise period you worked in California, then Texas, then Massachusetts, only the CA workdays factor into the CA-source calculation. The other workdays are ‘other state’ workdays that don’t go to California.
But your other states may also tax. Massachusetts, for example, has its own sourcing rules for stock options and may assert tax on the MA-source portion. Some states use grant-to-vest (like California), some use grant-to-exercise, some use only the year of exercise. The result: a person who lived in CA, then MA, then TX may have stock option income taxed by both CA and MA on overlapping periods, with credit-for-tax-paid issues.
Practical example: NQSO granted 2020 in CA (3 years there), moved to MA 2023 (2 years there), moved to TX 2025, exercised in 2026. Total grant-to-exercise period: 6 years. CA workdays: 3 years. MA workdays: 2 years. TX workdays: 1 year. CA-source: 50%. MA-source: 33%. TX-source: 17% (but TX has no income tax). The taxpayer files CA 540NR for the CA portion and MA Form 1-NR/PY for the MA portion. Both states will tax their respective slices; neither offers credit for the other (no resident return to claim credit against).
The taxpayer’s federal-resident state (TX in this case) doesn’t tax it. So the total state tax burden equals CA tax on 50% + MA tax on 33%.
Coordination tip: when filing nonresident returns in multiple states, calculate each state’s allocation independently using that state’s rules. Don’t assume California’s methodology applies in Massachusetts. Get a multi-state CPA involved if the dollars are meaningful.
Withholding and Estimated Tax Implications
California requires employers to withhold state income tax on the CA-source portion of equity comp income for current and former employees. EDD publishes withholding tables.
Common problem: employer withholds at the standard supplemental rate (10.23% for most equity comp in 2026 per EDD) on the full spread, not just the CA-source portion. The over-withholding shows up as a refund on Form 540NR if you file correctly.
Alternative problem: employer doesn’t withhold any CA tax because the employee is now an out-of-state resident. The CA-source portion is still owed at filing. The employee needs to make estimated payments or face a CA underpayment penalty under R&TC §19136.
Estimated tax thresholds in California: if you expect to owe more than $500 of CA tax beyond withholding, you should make estimated payments (Form 540-ES). For high earners, payments are due quarterly: April 15, June 15, September 15, January 15.
When equity comp exercise creates a big mid-year spike: the employee may need to make a large Q3 or Q4 estimated payment to avoid penalty. The ‘safe harbor’ rule allows you to pay 110% of prior-year tax (90% if AGI is under $150K) and avoid penalty regardless of current-year income — useful if a big exercise happens unexpectedly.
Coordination with new resident state: if you move to a state with income tax mid-year, both states’ withholding and estimated payments need attention. Florida, Texas, Nevada, etc. — no estimated payments needed for those states because there’s no income tax.
Common Mistakes Departing California Tech Workers Make
Pattern recognition from cases we see every year:
– Treating the move date as the cut-off for all California obligations. Stock comp doesn’t work that way. The look-back to grant date matters more than the move date.
– Failing to file a CA 540NR for vesting/exercise events post-move. The W-2 still shows CA wages (correctly allocated by the employer for prior service), and the FTB matches that. Not filing triggers a notice.
– Filing CA 540NR with zero CA allocation on equity comp, ignoring the grant-to-exercise/vest period. The FTB rejects this if the W-2 shows CA wages tied to the equity event.
– Trusting the employer’s allocation without checking. Large employers run sophisticated payroll, but mid-size and small companies often default to 100% CA or 0% CA without applying the workday methodology.
– Exercising ISOs while still a CA resident, then moving, then never being able to use the CA AMT credit because there’s no CA tax to offset.
– Working remotely for a California employer post-move and assuming the employer knows about the move. HR often doesn’t update payroll location automatically; the employee has to push.
– Not keeping move-date documentation: utility setup in new state, driver’s license update, voter registration, lease/closing on new home. These matter for both source allocation (workday tracking) and any FTB residency challenge.
Our recommendation: if you’re moving out of California with significant unvested or unexercised equity, get a multi-state tax planning conversation before the move. The right sequence (exercise ISOs same-day-sale vs. defer NQSO vs. accelerate exercise) depends on facts.
Filing Mechanics: Form 540NR and Schedule CA
Nonresidents with California-source income file Form 540NR. The form calculates California tax on California-source income using the ratio of CA AGI to total AGI applied to the tax liability computed on total income (effectively a ‘with-and-without’ methodology that prevents nonresidents from getting California’s lower brackets on small amounts of CA income).
Schedule CA (540NR) Part II reports the allocation between California-source and non-California-source income for each category. Equity compensation income is reported on the wages line with the California-source portion shown.
Backup documentation requested by FTB on audit:
– Grant agreements showing grant date and vesting schedule
– Exercise confirmations showing exercise date and number of shares
– Calendar or workday log showing California vs. non-California workdays during the grant-to-exercise (or grant-to-vest) period
– W-2 wage statements showing the equity compensation amount
– Move-date documentation (lease, closing, utility setup, license, voter registration in new state)
Filing deadlines: April 15, 2027 for the 2026 tax year. October 15, 2027 with extension (Form FTB 3519). California extensions are automatic if at least 90% of the tax owed has been paid by April 15 — but the extension is to file, not to pay.
Statute of limitations: 4 years from the later of the return due date or the date filed.
Frequently Asked Questions
I left California in March 2024 and have NQSOs from a 2021 grant that I'm planning to exercise in 2027. How much California tax will I owe on the exercise?
Depends on the math, but here’s how to work it out. The grant-to-exercise period runs from the grant date in 2021 through your exercise date in 2027 — call it 6 years and a few months, roughly 1,510 workdays at 252/year. Your California workdays during that period are January 2021 through March 2024 = approximately 3.25 years × 252 = 819 workdays. Your non-CA workdays (Texas, Florida, wherever you went) are roughly 2.75 years × 252 = 693 workdays. California allocation: 819 / 1,512 = 54%. So 54% of the spread at exercise is California-source.
If you exercise 5,000 options with a $90 spread (FMV of $100, strike of $10): total spread = $450,000. California-source portion = 54% × $450,000 = $243,000. California tax at the top marginal rate of 13.3% (assuming you’re in the top bracket, which $243K plus other income likely puts you in): approximately $32,300. The other 46% ($207,000) is non-California-source. If you’re now in a no-income-tax state like Texas or Florida, that portion is state-tax-free. If you’ve moved to another state with income tax, that state may claim it under its own sourcing rules — which may differ from California’s.
A few important nuances to work through with your CPA before the exercise. First, withholding. Your employer is supposed to withhold California income tax on the CA-source portion. In practice, employers handle this poorly for ex-California employees. Some withhold 13.3% on 100% of the spread (over-withholding by half), which you’d reclaim as a refund on Form 540NR. Others withhold nothing because they’ve classified you as out-of-state and didn’t apply the workday allocation. Notify payroll in writing before the exercise about your move date and ask for their methodology. Second, you’ll need to file Form 540NR for 2027 and attach Schedule CA showing the allocation. Bring the grant agreement, vesting schedule, and workday log. Third, if you can defer exercise further into the future, the allocation will dilute more — exercising in 2030 instead of 2027 would push the CA allocation closer to 35-40% as the denominator grows. The cost of deferring is that the spread typically grows too, so total CA tax in dollars may not actually drop. Run both scenarios.
The FTB will accept a reasonable workday allocation, but they’ll challenge a poorly-documented one. Keep records of your move date and any California business trips post-move, because each CA trip adds to your CA workday count. A weekly trip back to the San Francisco office for partner meetings will hurt your allocation significantly.
I exercised ISOs in 2023 while a California resident and held the shares. Now in 2026 I'm moving to Florida and plan to sell in 2027 to satisfy the §422 holding period. What happens to the California AMT credit I generated?
You’ve described the classic California ISO mover’s trap, and the news isn’t great. When you exercised the ISOs in 2023, the spread between strike and FMV became an AMT preference item under IRC §56(b)(3) and conforming California R&TC. You paid California AMT — let’s say 7% of the spread — and that AMT generated a California Minimum Tax Credit (FTB Form 3510) that you can apply against your regular California tax liability in future years.
The problem: once you move to Florida and become a nonresident, you have minimal or no California-source income going forward. The long-term capital gain from selling the ISO shares is intangible gain, not California-source under R&TC §17952 for nonresidents (assuming you sell after establishing Florida residency and the shares aren’t tied to California business operations). So the gain at sale isn’t taxed by California, which means there’s no California regular tax liability to absorb the AMT credit.
Result: the AMT credit sits on your California Form 3510 indefinitely. It doesn’t expire — California’s minimum tax credit has no expiration date — but it’s effectively unusable if you have no future California income. If you ever return to California or develop California-source income later (e.g., you take a California job, buy California rental property generating CA-source rental income, or sell CA real estate), you can use the credit then. But many movers never reactivate California income and the credit just sits there.
Partial mitigation: if you have California-source income in 2026 (the year of move) — like equity vesting from prior California service, deferred comp paid out from a CA job, or rental income from a CA property — you can apply the AMT credit against that year’s CA regular tax liability. So look at your full California exposure in your last year of CA residency or first year as nonresident. Sometimes there’s still meaningful CA tax to offset.
The lesson going forward: for someone planning to leave California within 1-2 years of an ISO exercise opportunity, the optimal strategy is often a same-day sale (disqualifying disposition) rather than holding for the §422 period. Same-day sale converts the ISO treatment to NQSO treatment — ordinary income on the spread at exercise, sourced based on grant-to-exercise workdays. No AMT preference. No California minimum tax credit trapped on the return. The federal tax difference between long-term capital gain (assuming you held for §422) and ordinary income (disqualifying disposition) is the rate spread of roughly 17-20 percentage points federally on the spread amount. But for someone moving to a no-tax state, eliminating the California AMT trap may be worth that rate cost — especially if the spread is large.
Don’t make this decision without running the numbers with a CPA who handles multi-state equity comp. The right answer depends on the spread size, your federal bracket, the expected capital gain at sale (if you hold), and how confident you are in the timing of your move.
I worked in California for 3 years on an H-1B visa, got NQSO grants, and now I've returned to India permanently. Will I still owe California tax on the options when I exercise them?
Yes, you almost certainly will. California source rules don’t care about your current residence or citizenship — they care about where you performed the services that earned the compensation. Your H-1B status and current residence in India don’t change the analysis. What matters is that you worked in California during the period that earned the options, so California claims a share of the income at exercise.
The mechanics: when you exercise the NQSOs as a nonresident (and as a nonresident alien for federal purposes), the spread between FMV and strike is compensation income. California gets the portion attributable to the grant-to-exercise workdays performed in California. If all of your service days during the grant-to-exercise period were in California (because you were in the US on H-1B working there continuously), then 100% of the spread is California-source even though you exercise from India.
If you’ve been out of California for some time before exercising and not working for the company anymore: the grant-to-exercise period still includes the time after you left California, but your non-California workdays during that period are zero (you’re not working anywhere — you’re either retired or working for a different employer in India). The denominator becomes problematic. The FTB’s general position: only working days for the granting employer count. If you’ve left the employer, the relevant period closes at separation. So the grant-to-separation period determines the allocation, and if all of those workdays were in California, 100% allocation.
Federal complication: as a nonresident alien at exercise, you owe US federal tax on US-source compensation income at NRA rates (often the highest brackets without standard deduction). The US-India tax treaty (Article 16 for dependent personal services) may provide relief if the services were performed entirely outside the US — but your services were performed in California, so the treaty doesn’t shield you.
Withholding mechanics: your employer should withhold federal income tax at NRA rates (30% under IRC §1441 for some categories) and California state tax on the CA-source portion. The actual tax owed when you file Form 1040-NR and Form 540NR may be more or less than what’s withheld; you’ll reconcile via the return.
Totem question: should you have exercised before leaving the US? Possibly. Exercising while a US resident gives you US-resident filing status (Form 1040 with standard deduction and graduated brackets), which is typically more favorable than NRA filing. But that locks in the spread at FMV at that time; if the stock appreciates significantly after you leave, you might have been better off exercising later as an NRA even with worse filing status. This is a fact-specific call that depends on stock trajectory and personal cash flow.
One more wrinkle: ITIN or ITIN-renewal issues. As a nonresident alien filing US tax returns, you need an ITIN. If yours has expired, renewal is part of the process. The IRS won’t process Form 1040-NR without a valid ITIN, and the California return ties to the federal. Plan for 4-6 weeks of ITIN processing time. Our expat tax preparation team handles this routinely for departing H-1B holders.
My California employer says they have to withhold California tax on 100% of my stock option spread even though I moved to Texas 2 years ago. Is this right?
Likely wrong, but the answer depends on what ‘have to’ means and how your payroll department handles it. California Employment Development Department (EDD) withholding rules require employers to withhold on California-source compensation. If only 50% of your equity comp is California-source under the workday allocation, the employer is supposed to withhold on the 50%, not 100%.
What happens in practice: many payroll systems are not sophisticated enough to apply per-employee workday allocations on equity comp. The default behavior at large California employers is to withhold California tax on 100% of the spread for any equity event tied to grants made during California employment, regardless of where the employee currently lives. This is over-withholding, but it’s safer for the employer than under-withholding (no EDD penalty exposure).
What you can do:
1. Push back at payroll. Send a written request to HR/payroll explaining that you moved to Texas on [date], have been performing all services for the employer remotely from Texas since that date, and that under California’s workday allocation rules, only [X]% of the equity spread is California-source. Ask them to recalculate withholding so. Some employers will accommodate; many won’t because their payroll systems don’t allow per-event manual allocation.
2. Accept the over-withholding and reclaim on Form 540NR. If the employer insists on 100% CA withholding, file Form 540NR for the year of exercise. Report the actual CA-source allocation on Schedule CA. Your California tax liability will be 50% × spread × applicable rate. The withholding shown on Form W-2 will be on 100% of the spread. The difference is your California refund. This is procedurally fine — California will refund the overpayment — but it means tying up cash for several months.
3. Make sure you don’t double-pay state tax. Texas has no income tax, so the non-CA portion isn’t taxed by Texas. But if you’d moved to Colorado or New York, the non-CA portion would be subject to your new state’s tax, and you’d file two nonresident or one resident + one nonresident return.
4. Document the workday allocation NOW. Don’t wait until exercise to assemble records. Calendar showing your CA presence (which should be zero or minimal post-move), business trip log if you visit California for work, and the grant agreement showing the vesting schedule.
5. Get the employer to update your tax residency in their records. Some companies have a ‘tax residency’ field in the payroll system separate from your mailing address. Both need to show Texas (or wherever your new home state is). Otherwise the system may keep treating you as a California employee for withholding purposes.
If this is a routine ongoing issue (multiple equity events over years), it may be worth changing employers’ payroll service or asking finance to engage an outside firm for the equity comp tax allocation. Some employers use specialized vendors for stock plan tax reporting that handle multi-state allocation correctly. Smaller companies often don’t.
Worst case: you pay California tax on 100% of the spread because the employer over-withholds and you don’t file the 540NR reclaim. The FTB will keep the money. We see this annually — ex-California employees who paid an extra $30K-$100K in California tax they didn’t owe simply because they didn’t push back on payroll and didn’t file the nonresident return. Filing the 540NR with proper allocation is the only way to recover the overpayment.
I'm getting an ISO grant next month and I'm pretty sure I'll move to a no-income-tax state within 2-3 years. Should I structure this differently?
Yes, this is exactly the conversation to have before the grant rather than after. A few things to think through:
First, what type of grant is it? ISOs come in two forms — single-employer ISOs and broader employee population ISOs — with the same federal tax rules but different practical patterns. For a smaller grant (under $100K of ISO value vested per year), the §422 $100K limit isn’t an issue. For larger grants, the portion exceeding $100K of FMV at grant per year automatically converts to NQSO treatment for federal purposes, which can change the planning.
Second, exercise timing matters more than grant timing. If you exercise the ISOs while a California resident and hold for the §422 holding period, you create a California AMT preference at exercise and a California AMT credit. If you then leave California before selling, the credit may strand on your return (as discussed in another FAQ). To avoid this trap:
– Same-day-sale exercise (disqualifying disposition) eliminates the AMT issue. The spread becomes ordinary income on your W-2 in the year of exercise/sale, sourced based on grant-to-exercise workdays. No AMT preference. No California minimum tax credit to worry about. The cost: ordinary-income rates instead of long-term capital gain rates.
– Defer exercise until after you’ve moved out of California. If you exercise as a nonresident, the California AMT preference is only on the CA-source portion of the spread. The credit (if any) is generated based on that smaller amount. If the spread is small and your CA-source portion is small, the AMT issue may not bite.
– Exercise and hold while a California resident only if you’re confident you’ll have meaningful California-source income for several years after the exercise to absorb the AMT credit. If you’re definitely leaving and your post-move California income will be near zero, holding through a move strands the credit.
Third, watch the 1-year vest cliff. Most ISO grants have a 1-year cliff before any vesting. If you receive the grant and move within 6 months, no shares have vested and there’s nothing to exercise yet — the planning question shifts to whether to stay long enough to vest at all.
Fourth, consider the §83(b) election if the grant is restricted stock rather than options. ISOs and NQSOs aren’t subject to §83(b) because options aren’t stock. But restricted stock grants (RSAs) are. A §83(b) election within 30 days of grant locks the source as wherever you currently work (California if granted while a CA employee) and starts the long-term capital gain clock. Useful if FMV at grant equals strike (so no current income), and you expect significant appreciation.
Fifth, structure the post-move work clearly. If you continue working remotely for the California employer after moving, those days are NOT California workdays under California rules (unlike New York’s convenience rule, California doesn’t have a convenience-of-employer rule for stock comp). So your CA-source allocation should drop sharply once you move, assuming you actually stop working in California. If you continue commuting back monthly for in-person meetings, those days count as CA workdays and dilute the benefit of the move.
Sixth, get the move clean. The FTB challenges ‘soft’ moves where the taxpayer keeps a California home, CA voter registration, kids in CA schools, etc. A residency audit can pull you back into California for the year of move (and sometimes subsequent years), which means you owe California tax on 100% of your income, including the stock comp, regardless of workday allocation. California residency rules are aggressive.
Seventh, factor in federal AMT separately. ISO exercise creates federal AMT preference too, not just California. Even if you’ve moved out of California, the federal AMT hit at exercise may be significant. Run the federal AMT scenario in parallel with the California analysis. Federal AMT planning is its own topic.
If the grant value is meaningful (over $500K of expected ISO value), get the structured planning done with a CPA who handles equity comp regularly. The grant-time decisions (whether to ask for ISOs vs. NQSOs vs. RSUs at grant negotiation, if you have use) can move six-figure dollars over the life of the grant. Decisions made at exercise can move similar dollars. The decisions made at exit (state of new residence, timing of sale, federal AMT credit usability) tie it all together. Talk to our equity comp team before the grant lands.
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