Iowa
$380
3.8% state
- Total withheld
- $3,345
- Net bonus
- $6,655
- Federal + FICA
- $2,965
- Rank
- #33
Compare different states
2026
2026Iowa vs California Bonus Tax
California withholds $643 more state tax than Iowa on $10,000 bonus with $80,000 year-to-date wages (flat supplemental method).
By Sammy S. · Founder · AuthorUpdated for 2026
Key finding
California withholds more state tax
$643 more state tax — net gap ~$643 ($6,655 vs $6,012).
Side-by-side bonus withholding scoreboard
California
$1,023
10.23% state
- Total withheld
- $3,988
- Net bonus
- $6,012
- Federal + FICA
- $2,965
- Rank
- #4
Total withholding gap: $643 (state drives most of the difference).
Key takeaways — Iowa vs California bonus tax
- California withholds about $643 more state tax ($380 vs $1,023).
- Iowa: 3.8% (Published flat supplemental). California: 10.23% (CA DE 44 bonus/stock (10.23%)).
- Federal withholding is $2,200 in both states on this vignette (22% flat per IRS Pub. 15); FICA is $765 each.
- Iowa ranks #33; California ranks #4 (#1 = highest state withholding).
- Model custom bonuses at /bonus-tax-calculator.
Rule contrast — Iowa vs California
| Topic | Iowa | California |
|---|---|---|
| Withholding method | Published flat supplemental | CA DE 44 bonus/stock (10.23%) |
| Supplemental rate | 3.8% | 10.23% |
| Vignette state tax | $380 | $1,023 |
| Vignette federal + FICA | $2,200 + $765 | $2,200 + $765 |
| Vignette total withheld | $3,345 | $3,988 |
| Vignette net | $6,655 | $6,012 |
| Rank (curated) | #33 | #4 |
State withholding and net at different bonus sizes
$80,000 YTD wages; engine flat supplemental method. State gap is state tax only; net columns include federal and FICA.
| Bonus | Iowa state | California state | State gap | IA net | CA net |
|---|---|---|---|---|---|
| $5,000 | $190 | $511.50 | $321.50 | $3,327.50 | $3,006 |
| $10,000 | $380 | $1,023 | $643 | $6,655 | $6,012 |
| $25,000 | $950 | $2,557.50 | $1,607.50 | $16,637.50 | $15,030 |
| $50,000 | $1,900 | $5,115 | $3,215 | $33,275 | $30,060 |
How to read this page
Iowa vs California bonus tax in 2026
This page compares state supplemental withholding for Iowa (IA) and California (CA) on $10,000 bonus with $80,000 year-to-date wages (flat supplemental method), calculated from our engine (same engine as the bonus calculator).
California is higher by about $643 in state tax alone; net take-home favors Iowa by about $643.
Published state supplemental withholding at 3.8% on bonus and other supplemental wages.
California DE 44: 10.23% flat on bonuses and stock options (other supplemental wages use 6.6%).
How each state’s rate works
Iowa (Published flat supplemental): about 3.8% → $380 on the vignette.
California (CA DE 44 bonus/stock (10.23%)): about 10.23% → $1,023 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 $2,200 federal income tax under the Pub. 15 flat method (22% on $10,000).
FICA is $765 in each (Social Security + Medicare on this YTD/bonus 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 bonuses, different state tax
The ladder recomputes engine results at $5k–$50k bonuses with $80,000 YTD wages.
When both sides use flat (or flat-PIT proxy) rates, the dollar gap scales roughly with bonus size.
Signing-bonus 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 Iowa vs California comparison helps
Useful if…
- •Candidates weighing Iowa vs California offers with cash bonuses
- •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
Iowa vs California checklist
Before treating the withholding gap as a job or relocation decision.
- 1Confirm Iowa and California supplemental rules with each revenue department.
- 2Ask which withholding method payroll uses (flat vs aggregate).
- 3Check the bonus ladder for your award size.
- 4Open /bonus-tax-by-state/iowa and /bonus-tax-by-state/california for full profiles.
- 5Run both scenarios in /bonus-tax-calculator.
Vignette net: $6,655 (IA) vs $6,012 (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 bonus calculator for custom amounts and YTD wages.
Iowa vs California bonus tax FAQs
California withholds about $643 more in state tax ($380 vs $1,023).
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.
Iowa: 3.8%. California: 10.23%.
Iowa, by about $643.
No. This comparison is state supplemental withholding plus federal and FICA only.
Not on this vignette. Both use 22% flat federal supplemental withholding ($2,200) plus the same FICA rules.
Compare another pair
Compare any two states
Supplemental bonus withholding on a $10,000 bonus with $80,000 YTD wages.
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