California RSU Source Rules: Vesting Income for Movers and Nonresidents
How California Sources Equity Compensation
California Revenue and Taxation Code §17041 and the implementing regulations under 18 CCR §17951-5 govern source-income rules for stock-based compensation. The basic principle: compensation is California-source to the extent the underlying services were performed in California, regardless of when the compensation is paid or vested.
Sourcing methodology for RSUs: at vesting, the income recognized equals the fair market value of the shares. California gets the portion of that income attributable to the period the RSU was earned (the vesting period) while you worked in California.
Formula: (CA workdays during vesting period / total workdays during vesting period) × total vesting income = California-source vesting income.
Example: 4-year RSU grant of 1,000 shares granted January 2022, vesting 25%/year (250 shares each year). You worked in CA all of 2022-2023, then moved to TX on January 1, 2024 and worked there 2024-2025. Vesting workdays: 4 years × ~252 workdays = 1,008 total. CA workdays: 2022-2023 = ~504. TX workdays: 2024-2025 = ~504.
When 250 shares vest in January 2026 (the final tranche): the vesting period is 4 years (2022-2026 grant-to-vest). CA workdays during vesting period = ~504 out of 1,008 = 50%. So 50% of the value of the vested 250 shares is CA-source.
If those 250 shares vest at $400/share = $100,000 vesting income. California-source: 50% × $100,000 = $50,000. California tax (at ~13.3% top rate, depending on overall income): approximately $6,650.
Key insight: even though you moved to Texas 2 years before vesting, California still gets 50% of the value because half the vesting period occurred while you worked in CA.
Per-tranche calculation: each vesting tranche is sourced independently based on its own vesting period. The first tranche vesting January 2023 (after 1 year vesting period in CA) is 100% CA-source. The last tranche vesting January 2026 (4 year vesting period, half in CA) is 50% CA-source.
The Vesting Period Definition
What counts as the ‘vesting period’ is the technical question that drives the math. California’s general approach: the vesting period is from grant date to vest date for each tranche.
Standard graded vesting: 4-year grant with 25%/year vesting and 1-year cliff. Vesting period for each tranche is from grant to that tranche’s vest date.
– 1st tranche (250 shares): vests year 1. Vesting period = 1 year.
– 2nd tranche (250 shares): vests year 2. Vesting period = 2 years.
– 3rd tranche (250 shares): vests year 3. Vesting period = 3 years.
– 4th tranche (250 shares): vests year 4. Vesting period = 4 years.
Each tranche’s California-source allocation is calculated based on its specific vesting period.
Cliff vesting: some grants vest 100% on a specific date (typically year 1 or year 3). Vesting period = grant to cliff date. All vested shares allocated based on workdays during that period.
Performance-based vesting (PSUs): when vesting depends on achieving performance milestones (not just time), California uses a similar approach but the vesting period is from grant to the date the performance condition is met.
Annual recalculation: each year California recalculates as new tranches vest. Your 2026 California tax return reports the 4th tranche’s vesting (50% CA-source if you moved mid-vesting period). Your 2024 return reported the 2nd tranche differently.
Disputed approaches: some practitioners argue for shorter ‘vesting period’ definitions (e.g., the year of vesting only, not the full grant-to-vest period). California has consistently used the grant-to-vest period in audit and litigation. Don’t try to be clever with shorter periods unless you have specific authority supporting it.
RSUs vs. Stock Options vs. ISOs — Different Mechanics
Different equity compensation types have different sourcing rules. Don’t conflate them.
RSUs (Restricted Stock Units): no purchase event. At vesting, you receive shares and recognize ordinary income equal to FMV. California sources based on grant-to-vest workdays.
NQSOs (Non-Qualified Stock Options): you have to exercise to get income. At exercise, the spread (FMV minus exercise price) is ordinary income. California sources based on grant-to-exercise workdays (NOT grant-to-vest).
Practical difference: NQSO sourcing locks at grant-to-exercise. You can defer exercise to lengthen the vesting period and dilute the CA-source allocation. RSU sourcing is locked at grant-to-vest, which you can’t change.
Example: NQSO granted while in CA in 2022 with 10-year exercise window. You move to TX in 2024 but don’t exercise until 2030. Vesting period for sourcing: grant-to-exercise = 2022-2030 = 8 years. CA workdays during vesting period: 2022-2023 = ~504 out of 8 years × 252 = ~2,016. CA portion: 504/2,016 = 25%. Substantially diluted from the 50% you’d have if you exercised in 2026.
ISOs (Incentive Stock Options): exercise creates AMT income (not regular income) if you hold the shares. Sale of the underlying stock creates capital gain. California’s source rules apply similarly to ISOs as to NQSOs for AMT purposes — based on grant-to-exercise workdays.
RSAs (Restricted Stock Awards): different from RSUs. At grant, you receive shares but they’re forfeitable. If you make a Section 83(b) election within 30 days, you recognize income immediately (sourced where you worked at grant date). Without §83(b), you recognize income at vesting (sourced over the grant-to-vest period).
ESPPs (Employee Stock Purchase Plans): complex. The ‘qualified discount’ element follows the offering period; the spread at sale is partly compensation, partly capital gain. California source rules for the compensation element follow service performance during the offering period.
Movers' Math: Working Through a Departing California Employee's Situation
Real-world example: Maria, software engineer at a SF tech company. Hired 2022. Granted 4,000 RSUs vesting 25%/year over 4 years starting 2023. Worked in SF 2022-2024. Moved to Austin, TX in January 2025 and continued working remotely for the SF company.
RSU vesting and CA source allocation:
1st tranche (1,000 RSUs vesting January 2023): vesting period = grant date 2022 to vest 2023 = 1 year. All CA workdays. 100% CA-source.
2nd tranche (1,000 RSUs vesting January 2024): vesting period = 2022 to 2024 = 2 years. All CA workdays during vesting period. 100% CA-source.
3rd tranche (1,000 RSUs vesting January 2025): vesting period = 2022 to 2025 = 3 years. 2022-2024 = 3 years in CA = 100% CA workdays during vesting period (she moved January 1, 2025, after the 3-year vesting period ended). 100% CA-source.
4th tranche (1,000 RSUs vesting January 2026): vesting period = 2022 to 2026 = 4 years. CA workdays: 3 years (2022-2024). TX workdays: 1 year (2025). CA portion: 3/4 = 75%. 75% CA-source.
Each vesting event creates W-2 income at the company’s payroll. The company likely withholds California state tax on the CA-source portion. For the 4th tranche vesting at $400/share: 1,000 shares × $400 = $400,000 income. CA-source = 75% × $400,000 = $300,000. CA tax at ~13.3% top rate on the CA-source portion: ~$40,000.
If Maria thought ‘I moved to Texas before vesting, so no CA tax’: wrong. CA collects ~$40K on the 4th tranche alone, plus the earlier tranches at 100% CA-source.
Texas residency benefit: Maria’s other 25% of the vesting income (TX-source) is not state-taxed (TX has no income tax). Federal tax applies fully. NIIT may apply on portions depending on her overall income.
Tracking duty days matters: if Maria worked in CA part of 2025 (visiting clients, etc.), those CA workdays count toward the CA workday total in 2025. Increasing the CA share. Conversely, if she had worked outside CA before her move (e.g., 2024 had some non-CA travel), those workdays could reduce CA share.
Documentation: keep records of where you physically worked each day. Calendars, expense receipts (showing locations), travel records, employer records. The CA FTB can audit equity compensation sourcing and request documentation.
California's Aggressive Audit Position
The FTB audits high-income equity compensation recipients aggressively, particularly those who moved out of California after substantial RSU grants. The audit focus: did the taxpayer properly source the income, or did they under-allocate to California?
Common audit patterns:
– Former CA tech worker who ‘forgot’ to file CA non-resident return after moving. The FTB knows about the equity events via employer W-2 reporting (the company reports state withholding to CA). If the worker didn’t file a CA return reporting the income, the FTB flags it.
– Worker who claimed all post-move income was non-California source. The FTB recalculates with the grant-to-vest period and assesses additional CA tax plus penalties.
– Worker who reduced the CA workday count by claiming days they were technically in CA didn’t count (vacation days, etc.). The FTB tightens the count.
Documentation under audit: the FTB asks for proof of where you worked each day during the vesting period. Travel records, calendars, work logs, employer records. If you can’t substantiate non-CA workdays, the FTB defaults to assuming you were in CA.
Tip the FTB shouldn’t be: don’t try to argue that less than the full grant-to-vest period is the ‘vesting period.’ California has consistently used this approach and won’t entertain creative redefinitions.
Penalty exposure: failure to file CA nonresident return (Form 540NR) creates failure-to-file and failure-to-pay penalties separately from the underlying tax. Combined penalty + interest can add 25-40% to the tax bill.
Statute of limitations: typically 4 years from CA filing date. Longer for substantial under-reporting. Indefinite for fraud or no filing at all. Failure to file an IT-203 nonresident return when required leaves the statute open indefinitely.
Voluntary compliance: if you discover you under-allocated CA source income in prior years, voluntarily amending returns is much cheaper than waiting for audit. California has voluntary disclosure programs for taxpayers coming into compliance.
Planning Moves to Reduce California RSU Tax
Limited but real planning opportunities exist:
Strategy 1: Time your move strategically. If you have RSUs vesting soon, moving before vesting captures the post-move workdays for non-CA sourcing on that tranche. Moving the day after a tranche vests means that tranche is 100% CA-source. Moving the day before captures one fewer CA workday.
Strategy 2: Defer NQSO exercise (not RSUs — they don’t have exercise to defer). For NQSOs, you can wait to exercise. Each year of additional post-move work dilutes the CA-source allocation. RSUs vest automatically; no deferral available.
Strategy 3: Pre-move equity acceleration. Some employers will accelerate vesting before an employee leaves (e.g., as part of a transition package). If RSU vesting accelerates to occur while you’re still in CA, the CA-source allocation is high but you avoid the multi-year recalculation. Whether to accelerate is fact-specific.
Strategy 4: Stay in a non-tax state during peak vesting years. If you can structure your career to be a non-CA resident during years of high-value vesting, you reduce CA tax on those tranches. Practical for those with employer flexibility.
Strategy 5: Don’t move to another high-tax state. If you move from CA to NY/NJ, you trade CA tax for NY tax. To get state tax savings, you need to move to a no-state-tax state (TX, FL, NV, WA, etc.).
Strategy 6: Roth IRA contributions and 401(k) catch-up. Federal traditional retirement contributions reduce AGI, which can reduce both federal and state tax on the same income. Doesn’t help with state-source allocation but reduces overall tax burden.
Strategy 7: Charitable contributions in high-RSU-vest years. Bunching charitable gifts in years with substantial RSU vesting reduces federal taxable income, which California follows. Mitigates the federal tax bill on RSU vesting; doesn’t directly reduce the CA-source portion.
Strategy 8: §83(b) election timing for RSAs. For Restricted Stock Awards (not RSUs), filing §83(b) within 30 days of grant accelerates income to the grant year — sourced to where you worked at grant. If grant occurred in a non-CA state, the §83(b) election locks in non-CA sourcing.
What doesn’t work:
Claiming the workdays before grant or after vest. The sourcing window is grant-to-vest period. Days outside that window don’t dilute.
Arguing that you ‘really’ worked from home in a non-CA location while officially employed in CA. The FTB checks employer payroll records, which show CA assignment. You need to actually be working elsewhere.
Sham residency changes (paper moves without actually leaving CA). The FTB audits residency aggressively for former CA residents who claim post-move equity events.
We work with departing CA tech workers on equity tax planning. The mechanics are largely fixed, but timing decisions on moves, exercise of options, and equity acceleration can save substantial CA tax over the full vesting cycle.
Frequently Asked Questions
I worked in CA for 2 years on my 4-year RSU grant, then moved to FL. How much of my future vesting will be CA-source?
Decreasing over each remaining tranche, ending at 50% for the final tranche. Specific math depends on your vesting schedule.
Standard 4-year grant with 25%/year graded vesting:
Year 1 tranche (250 shares): vested while in CA. 100% CA-source.
Year 2 tranche (250 shares): vested while in CA. 100% CA-source.
Year 3 tranche (250 shares): vests after you moved to FL. Vesting period = grant to year 3 = 3 years. CA workdays during vesting period: years 1-2 = 2 years in CA. FL workdays during vesting period: year 3 = 1 year in FL. CA share: 2/3 = 67%. 67% CA-source.
Year 4 tranche (250 shares): vests after FL move. Vesting period = grant to year 4 = 4 years. CA workdays: 2 years. FL workdays: 2 years. CA share: 2/4 = 50%. 50% CA-source.
Total CA-source over the 4-year grant: tranches 1-2 fully CA, tranche 3 at 67%, tranche 4 at 50%. Average across the grant: ~79% CA-source.
If you’d stayed in CA through full vesting: 100% CA-source on all tranches.
Tax math on $1M total grant value (assuming each tranche vests at $250K): CA tax savings from moving = (21% reduction in CA-source × $1M) × CA top rate 13.3% = $28K of CA tax savings over the remaining vest. Modest given the dollar amount but real.
FL benefit: post-move workdays’ income is FL-source = no state tax. So tranche 3’s 33% FL-source portion ($82.5K) saves whatever your state tax would have been ($11K if CA). Tranche 4’s 50% FL-source portion ($125K) saves ~$17K.
Federal tax: same regardless of state. Vesting income is W-2 wages, taxed at ordinary rates plus 1.45% Medicare (or 2.35% on amounts over $200K single / $250K MFJ). Plus 0.9% Additional Medicare Tax on high earners.
Withholding mechanics: when the company processes the vesting, they withhold federal income tax, FICA, plus state withholding based on the allocation they’re tracking. For a former CA employee now in FL, the company should withhold the CA-source portion of state tax. Sometimes employer payroll systems miss the allocation and over-withhold (treating all vesting as CA-source). You’d file CA Form 540NR to claim refund of over-withheld amounts.
Documentation: keep records showing your work location during the vesting period. Employer email records, calendar, home address changes registered with HR. Helps if FTB audits the allocation.
Multi-state filings: in vest year 3 (when you’re in FL but recognizing CA-source income), file: federal Form 1040, CA Form 540NR reporting CA-source vesting income, no FL state return (FL has none). Year 4 same pattern.
We help departing CA tech workers with multi-year equity tax planning and Form 540NR filings. The mechanics are predictable once you understand the sourcing methodology.
If I work remotely for my CA company from outside CA, do those workdays count as non-CA for RSU sourcing?
Generally yes — workdays performed outside CA are non-CA workdays for sourcing purposes, regardless of whether your employer is CA-based. California sources based on where YOU were physically working, not where the employer is.
This is different from New York’s convenience-of-the-employer rule (see New York Source Income Rules). NY treats remote work for a NY employer as NY-source even if you’re physically elsewhere. California does NOT have this rule. CA sources based on physical workdays.
Practical implication: a former CA tech worker who moved to Texas but continues working for the CA-based employer has Texas workdays for the post-move period. Those workdays are TX-source (not CA-source) under CA’s rules.
Caveat: some specific industries and arrangements have different rules. Professional services with substantial CA-based service delivery, or sales personnel covering CA territory, can have nuanced sourcing. For typical software engineer / product manager / similar remote tech worker situations, physical workday allocation applies.
What ‘physically working’ means: where you actually performed work. Trips to CA for company meetings count as CA workdays (typically full days if you were in CA most of the day). Days spent at conferences in CA count as CA workdays.
Vacation and personal time: not workdays. Don’t include in either numerator or denominator. Your ‘1-year vesting period’ might be 252 workdays excluding weekends, holidays, and PTO.
Documentation: keep records of work location for each day. Email metadata showing location, calendar entries, credit card/expense locations, hotel records for any business travel, photos with metadata. The FTB can audit and request granular documentation.
Aggressive position: some workers argue that occasional CA business trips while otherwise working remotely from a non-CA location shouldn’t count as CA workdays because the ‘principal work location’ is elsewhere. CA doesn’t accept this — even occasional CA workdays count.
Common scenarios:
Scenario A: TX-resident working fully remote from TX home for CA employer, occasional CA visits (3-5 days/year for company offsites). Almost all workdays are TX-source. CA visits add small CA-source amounts to the allocation.
Scenario B: TX-resident working from TX home most of the time but spending 1 week/month in CA office. Roughly 12 weeks/year × 5 days = 60 days CA per year. Out of ~252 workdays: 24% CA workdays. Significant CA-source allocation.
Scenario C: dual-residence professional spending half the year in CA, half in TX. ~126 CA workdays out of 252 = 50% CA-source. Substantial CA tax even with TX residence.
If your company tracks work location through payroll systems: their records likely align with CA-source allocations they apply. Verify the records match your actual work location. Disputes between your records and the company’s can create issues.
What if my RSU value crashed between grant and vesting — does CA still tax the original allocation?
California taxes the actual income recognized at vesting, which is the FMV at vesting (not the grant value). So if the stock crashed, you pay tax on the lower (crashed) value. The CA-source allocation is the same percentage, but applied to a smaller amount.
Example: 1,000 RSUs granted in 2022 at $500/share grant-date value ($500K theoretical grant value). Stock crashes to $100/share by vesting in 2026. Vesting income recognized: 1,000 × $100 = $100,000. The $500K grant value is irrelevant for tax purposes — only the vesting value matters.
If you were 50% CA-source: 50% × $100,000 = $50,000 CA-source. CA tax at ~13.3%: ~$6,650.
Compare to the $500/share scenario: vesting income $500K, CA-source $250K, CA tax ~$33K. The stock crash saved you $26K of CA tax.
But: federal tax on vesting income is also lower with crashed stock. So overall less tax revenue, less benefit to you compared to if the stock had appreciated. Crashed RSUs are bad news regardless of CA implications.
Capital loss on subsequent sale: if you hold the vested shares and they continue to decline, you can claim capital loss when you eventually sell. But that loss is unrelated to the vesting income for sourcing purposes — separate calculation.
What if stock appreciated significantly between grant and vest: more vesting income, more CA tax, but generally good news for you. RSUs are designed to capture the upside.
Cost basis after vesting: your basis in the vested shares is the FMV at vesting (the amount you recognized as income). Subsequent gain or loss when you sell is calculated from that basis.
Holding period: starts at vesting for capital gains purposes. Held > 1 year after vesting = long-term capital gain rate (20% top) if sold at a gain. Held < 1 year = short-term capital gain at ordinary rates.
Strategic considerations:
– If stock is declining and you have a year’s worth of vested-but-unsold shares, selling now might lock in a smaller capital loss than waiting for further decline.
– If stock is volatile and could recover, holding might capture appreciation.
– If you have other capital gains, selling at a loss now can offset gains, providing tax benefit.
Tax loss harvesting on vested shares is independent of the vesting-source allocation. The CA-source portion is locked at vest based on the workday allocation; the subsequent gain/loss has its own state sourcing rules (typically based on where you live when you sell, not where you worked when you vested).
We help tech workers with sell decisions on vested RSUs, particularly for stocks that have crashed where loss harvesting may make sense. The mechanics are fact-specific and depend on the worker’s overall portfolio and tax situation.
My company pre-vest accelerates RSUs as part of a layoff package. Does that change CA tax?
Yes — substantially. Acceleration changes the vesting date and so the vesting period for sourcing. If acceleration occurs while you’re a CA resident or shortly before move, the CA-source allocation is higher than if vesting had proceeded on the original schedule.
Mechanics: when RSUs are pre-vest accelerated, the income recognized is the FMV at the acceleration date (not the original vesting date). The vesting period for sourcing purposes ends at the acceleration date.
Example: 4-year RSU grant from 2022. As of 2025 (3 years in), 1,000 RSUs are unvested across years 3-4. You’re laid off in March 2025 while still working in CA. The company accelerates the remaining 1,000 RSUs to fully vest as of March 2025.
Sourcing: vesting period = grant date 2022 to acceleration date March 2025 = approximately 3 years. CA workdays during that period: all of 2022-2024 (3 full years) = 100% CA workdays. CA-source of accelerated vesting: 100%.
Compare to original schedule (no acceleration, you moved to TX after the layoff): tranche 3 vesting 2025 might have had some TX workdays if vesting were later in 2025 and you’d moved. Tranche 4 vesting 2026 would have been split between CA and TX.
Practical effect: acceleration locks in higher CA-source allocation if it occurs while you’re in CA. This is generally bad for you tax-wise compared to letting vesting occur after your move.
Counter-argument: acceleration eliminates the risk of forfeiture if you leave (you keep the shares). So you trade higher CA tax for certainty. Some workers accept this; others negotiate to extend vesting periods (not accelerate them) to allow for post-move vesting.
Negotiation point in severance: if you have use with the company (executive level, key contributor), you can sometimes negotiate alternatives to standard acceleration. Examples: extend the vesting cliff into your move period, defer vesting to occur after departure (with the understanding that you remain on the books as employed during the deferral period), accelerate to specific dates that fall after your planned move.
Tax-driven decision: pure tax optimization might argue against acceleration. But tax isn’t the only factor — severance also includes salary continuation, benefits, COBRA, and other terms. Accept the package as a whole or negotiate specific items.
Documentation: keep the severance agreement and acceleration paperwork. The accelerated vesting amount and date are documented for tax purposes.
Timing of stock sale: after accelerated vesting, you own the shares. Subsequent sale generates capital gain/loss. CA-source treatment for the sale depends on your residency at sale (you might be a TX resident by then, eliminating CA tax on the capital gain).
We help departing employees model tax implications of acceleration vs alternatives. For senior employees with substantial unvested equity, the math matters.
My company has a 'modified vesting' schedule where RSUs vest faster after I hit certain milestones. How does CA source those?
Performance-based vesting (PSUs or RSUs with non-time vesting conditions) follow similar sourcing principles but the vesting period definition is more nuanced.
Two main categories of non-standard vesting:
PSUs (Performance Stock Units): vesting depends on the company hitting specific performance metrics (revenue targets, stock price thresholds, etc.). California sources based on the period from grant to the date the performance condition is met (or measurement date for the performance period).
Modified RSU schedules: regular RSUs with vesting acceleration triggered by specific events (IPO, change in control, hitting individual performance goals). Source based on grant to actual vest date.
PSU specific mechanics:
Performance period: typically 1-3 years. Grant date to end of performance period.
If performance is met: shares vest as of end of performance period. Income recognized = FMV at vest.
Sourcing: based on workdays during the performance period (grant date to vest date).
Example: PSU grant January 2022 with 3-year performance period (vest December 2024 if performance hit). Performance achieved, you vest 1,000 shares at $300/share = $300K.
If you worked in CA 2022-2023 and moved to FL January 2024: CA workdays = 2 years. FL workdays = 1 year. CA-source = 67%. CA tax on $200K (67% × $300K) at ~13.3% = ~$27K.
RSU with IPO trigger: standard time-based vesting accelerated by an IPO event. Vesting occurs at IPO date (regardless of original 4-year schedule). Sourcing based on grant to IPO date.
Example: RSU granted 2022 with 4-year time vesting, accelerated by IPO trigger. Company IPOs in March 2025. All unvested RSUs vest at IPO. You moved to TX in January 2025. Vesting period = grant 2022 to vest March 2025 = ~3.25 years. CA workdays: 2022-2024 = 3 years. TX workdays: Jan-March 2025 = 0.25 years. CA-source = 3 / 3.25 = 92%. Most of the IPO vesting is CA-source despite your TX move.
Change in control acceleration: similar mechanics. If your company is acquired and your RSUs accelerate to full vest at closing, sourcing is based on grant to closing date.
Strategic considerations:
PSUs are hard to plan around because the vesting date depends on performance achievement, which isn’t entirely in your control.
Time-based RSUs with potential acceleration triggers (IPO, M&A) require timing of personal moves before the trigger if you want to capture post-move workdays.
Knowing your grant terms: review your equity grant documents to understand vesting schedules, accelerators, and triggers. Different employees can have different terms.
Documentation: keep records of vesting dates, FMV at vesting, and your work location during the vesting periods. The complexity of non-standard vesting makes documentation more important.
Federal taxation: same regardless of state. The wages are W-2 income at the FMV at vesting, withholding occurs at vesting.
We help employees with complex equity packages including PSUs and accelerated RSUs. The tax planning is fact-specific and requires understanding both the equity terms and the worker’s residency timeline.
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