Illinois
$2,475
~4.95% PIT state
- Total withheld
- $16,339
- Net RSU
- $33,661
- Federal + FICA
- $13,864
- Rank
- #24
Compare different states
2026
2026Illinois vs California RSU Tax
California withholds $2,640 more state tax than Illinois on $50,000 RSU vest (100 shares × $500 FMV) with $150,000 other annual income (flat supplemental method).
By Sammy S. · Founder · AuthorUpdated for 2026
Key finding
California withholds more state tax
$2,640 more state tax — net gap ~$2,640 ($33,661 vs $31,021).
Side-by-side RSU withholding scoreboard
California
$5,115
10.23% state
- Total withheld
- $18,979
- Net RSU
- $31,021
- Federal + FICA
- $13,864
- Rank
- #4
Total withholding gap: $2,640 (state drives most of the difference).
Key takeaways — Illinois vs California RSU tax
- California withholds about $2,640 more state tax ($2,475 vs $5,115).
- Illinois: ~4.95% PIT (Flat PIT proxy (no separate table)). California: 10.23% (CA DE 44 RSU/stock (10.23%)).
- Federal withholding is $11,000 in both states on this vignette (22% flat per IRS Pub. 15); FICA is $2,864 each.
- Illinois ranks #24; California ranks #4 (#1 = highest state withholding).
- Model custom RSU vests at /rsu-tax-calculator.
Rule contrast — Illinois vs California
| Topic | Illinois | California |
|---|---|---|
| Withholding method | Flat PIT proxy (no separate table) | CA DE 44 RSU/stock (10.23%) |
| Supplemental rate | ~4.95% PIT | 10.23% |
| Vignette state tax | $2,475 | $5,115 |
| Vignette federal + FICA | $11,000 + $2,864 | $11,000 + $2,864 |
| Vignette total withheld | $16,339 | $18,979 |
| Vignette net | $33,661 | $31,021 |
| Rank (curated) | #24 | #4 |
State withholding and net at different RSU sizes
$150,000 other annual income; engine flat supplemental method. State gap is state tax only; net is after-tax share value after sell-to-cover.
| RSU | Illinois state | California state | State gap | IL net | CA net |
|---|---|---|---|---|---|
| $15,000 | $742.50 | $1,534.50 | $792 | $9,810 | $9,018 |
| $50,000 | $2,475 | $5,115 | $2,640 | $33,661 | $31,021 |
| $100,000 | $4,950 | $10,230 | $5,280 | $69,011 | $63,731 |
| $250,000 | $12,375 | $25,575 | $13,200 | $175,061 | $161,861 |
How to read this page
Illinois vs California RSU tax in 2026
This page compares state supplemental withholding for Illinois (IL) and California (CA) on $50,000 RSU vest (100 shares × $500 FMV) with $150,000 other annual income (flat supplemental method), calculated from our engine (same engine as the RSU vest calculator).
California is higher by about $2,640 in state tax alone; net take-home favors Illinois by about $2,640.
No separate supplemental table; educational estimate uses the state’s flat PIT ≈4.95%.
California DE 44: 10.23% flat on bonuses and stock options / RSUs (other supplemental wages use 6.6%).
How each state’s rate works
Illinois (Flat PIT proxy (no separate table)): about 4.95% → $2,475 on the vignette.
California (CA DE 44 RSU/stock (10.23%)): about 10.23% → $5,115 on the vignette.
Official state agencies for this pair only are linked in the sources section — not every state in the hub.
Federal and FICA are the same on this vignette
Both states withhold $11,000 federal income tax under the Pub. 15 flat method (22% on $50,000).
FICA is $2,864 in each (Social Security + Medicare on this YTD/RSU pair). The take-home gap is almost entirely state supplemental withholding.
Above $1M supplemental wages with one employer, federal withholding uses 37% on the excess — still the same rule in both states.
Same RSU vests, different state tax
The ladder recomputes engine results at $15k–$250k RSU vests with $150,000 other annual income.
When both sides use flat (or flat-PIT proxy) rates, the dollar gap scales roughly with RSU size.
Signing-RSU negotiations should still include regular wage tax and cost of living — not supplemental withholding alone.
What this comparison excludes
Local city taxes (NYC, Philly wage tax, Ohio municipalities) are not included.
Aggregate-method stubs can differ from the flat-percentage estimates shown here.
Final Form 1040 liability depends on annual brackets, deductions, and credits — withholding is a prepayment.
Who this Illinois vs California comparison helps
Useful if…
- •Candidates weighing Illinois vs California offers with cash RSU vests
- •Payroll comparing multi-state supplemental setup
- •Editors quantifying high-tax vs no-tax state gaps
Use official tools if…
- •Local city taxes (NYC, Philly, Ohio municipalities)
- •Aggregate-method stubs that differ from flat rates
- •Year-end true-up if federal 22% under-withholds
Illinois vs California checklist
Before treating the withholding gap as a job or relocation decision.
- 1Confirm Illinois and California supplemental rules with each revenue department.
- 2Ask which withholding method payroll uses (flat vs aggregate).
- 3Check the RSU vest ladder for your award size.
- 4Open /rsu-tax-by-state/illinois and /rsu-tax-by-state/california for full profiles.
- 5Run both scenarios in /rsu-tax-calculator.
Vignette net: $33,661 (IL) vs $31,021 (CA).
What the state gap means
Flat supplemental rates differ by state; federal 22% and FICA rules are the same. Withholding is not your final tax bill when you file.
Limits of this comparison
NYC/local taxes, aggregate-method withholding, and equity vest timing are not modeled. Use the RSU calculator for custom vest amounts and other income.
Illinois vs California RSU tax FAQs
California withholds about $2,640 more in state tax ($2,475 vs $5,115).
No on this vignette — both use the flat 22% federal supplemental method plus the same FICA rules. The gap is almost entirely state supplemental withholding.
Illinois: ~4.95% PIT. California: 10.23%.
Illinois, by about $2,640.
No. This comparison is state supplemental withholding plus federal and FICA only.
Not on this vignette. Both use 22% flat federal supplemental withholding ($11,000) plus the same FICA rules.
Compare another pair
Compare any two states
Supplemental RSU withholding on a $50,000 vest (100×$500) with $150,000 other income.
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