Live in California, work in Arizona

From paycheck withholding to your returns

1. Withholding: A qualifying California resident working in Arizona can give the employer Arizona Form WEC, Part 3, if allowed the nonresident credit against Arizona tax for tax paid to California. This is a conditional withholding exemption, not wage reciprocity or an exemption from filing. The 2026 WEC instructions require a new certificate each calendar year; keep a copy and notify payroll if eligibility changes. Arrange adequate California resident withholding or review California's 2026 Form 540-ES instructions. A zero-withholding election on Arizona A-4 is a different procedure from claiming WEC eligibility.
2. Returns: Prepare the California resident return first, including the Arizona wages, to establish California tax on the shared income. Then prepare Arizona nonresident Form 140NR, subject to its filing requirements, and calculate the eligible Arizona credit on Form 309. Include Arizona Form 301 and Form 309 with the Arizona return. Retain the California return and proof of payment for Arizona's substantiation requests. The Arizona official 140NR and 309 pages list 2025 annual forms, published January 1, 2026; they are not 2026 tax-year returns. Use the final annual editions for the year being filed.
3. Credit or refund: For this full-year California-resident wage route, the credit belongs on the Arizona nonresident return. California Schedule S instructions deny a California credit when the other state allows California residents credit for California net income tax. Do not claim a second California credit for the same Arizona wages. Arizona Form 309 limits the credit using the same income taxed by both states and eligible net income tax, after applicable credits; W-2 withholding alone does not establish the credit. A credit cannot exceed the applicable Arizona limit and need not erase every Arizona balance.

Worked example: $100,000 of wages

Single filer, full-year resident of California, all work performed in Arizona, no other income, standard deductions and modeled personal exemptions. Before credit, Arizona tax is $2,098. Modeled Arizona credit: $2,098. Pay $0 to Arizona and $4,911 to California, modeled total $4,911.

The existing 2026 planning model is unchanged. Arizona's modeled $16,100 single deduction assumes federal-standard-deduction conformity; confirm the final filing-year Arizona deduction and conformity treatment. The linked 2025 Form 140NR, Form 309 and Form 301 requirements do not certify final 2026 annual-return amounts. California uses published 2026 indexed planning inputs; special credits and return-level adjustments are outside the estimate.

Annual liability, not paycheck withholding or a refund estimate. Federal tax, payroll programs, other local taxes, special credits and part-year residency are excluded. Local income taxes not included.

Remote-work and local exceptions

This example assumes full-year California residence and all ordinary employee services physically performed in Arizona. California taxes its resident's income regardless of source. Arizona Form 140NR instructions include wages for services performed in Arizona in its Arizona column. California home-working days therefore require a separate Arizona sourcing review and work-location records; this calculator does not allocate them. A move, dual residence, equity compensation, business income or pass-through tax credit is outside this wage example.

California resident, Arizona job: put the credit on the Arizona return

For a California resident whose ordinary job is entirely in Arizona, prepare the California resident return before calculating Arizona Form 309. Carry the eligible result through Arizona Form 301 to the Arizona nonresident return, and retain the California return and payment evidence. Do not repeat that credit on California Schedule S. Even if a qualifying WEC stops Arizona withholding during the year, check whether Arizona Form 140NR is required. This example does not quote a refund or calculate local taxes.

Official forms and instructions

• Arizona WEC (2026): Part 3 for qualifying California-resident employees (opens in new tab)
• Arizona WEC instructions (2026): conditions, annual renewal and employer submission (opens in new tab)
• Arizona Form 140NR official landing: 2025 nonresident annual form and instructions (opens in new tab)
• Arizona Form 309 official landing: 2025 annual credit form and instructions, not a 2026 return (opens in new tab)
• Arizona Form 309 instructions (2025 edition): Form 301, eligible net tax and substantiation (opens in new tab)
• California Schedule S instructions (2025 edition): reverse-credit restriction (opens in new tab)
• California resident filing guidance: income taxed regardless of source (opens in new tab)
• California Form 540-ES instructions (2026): estimated payments and DE 4 adjustment (opens in new tab)

Source audit 2026-11-01. Use the return and instructions for the year you are filing; a current-forms link may still show a prior-year return. Official sources checked; not independently reviewed.

Check your payslip and keep these records

• Compare the payroll certificate you supplied with the state withholding on your next payslip. Check city, county and school-district entries separately; a state exemption does not settle local tax.
• Keep your W-2 and other withholding statements, copies of payroll certificates, filed state and local returns, and proof of tax paid. A refund depends on actual withholding and the completed return, not this annual estimate.
• Keep an actual work-location log, including home-working days. This calculator assumes ordinary employee wages, full-year residence in California and every workday physically in Arizona.
• If you moved during the year, have nonwage income or do not meet that scope, follow the pair's remote and local exceptions and the moving-year tax guide before using the amount as your own result. This tool does not calculate hybrid allocation, local credits or a personal refund.