Before you start

An SSN or ITIN
Form W-4 with your employer for federal withholding
Arizona Form A-4 for state withholding — you must choose a percentage
Records of foreign income and foreign financial accounts

Step-by-step

1
Complete the W-4 and the Arizona A-4 on day one
Arizona's withholding certificate asks you to select a withholding percentage rather than deriving it from the federal form. If you do not file an A-4 the employer applies a default rate, which is frequently wrong for your situation. It takes two minutes and prevents an April surprise.
Via employerWho: YouFirst week of employment
2
Check you are being paid Tucson's minimum wage, not Arizona's
The Tucson Minimum Wage Act sets a city floor of USD 15.45 an hour from 1 January 2026 against Arizona's USD 15.15, with tipped work at USD 12.45 and a maximum tip credit of USD 3.00. It applies to work performed inside the city limits and is enforced by the city's Business Services Department. An employer quoting the state figure for a Tucson job is quoting the wrong number.
Via employerWho: YouFirst payslip
3
Determine your US tax residency
The substantial presence test counts weighted days across three years to decide whether the US taxes your worldwide income or only US-source income. Certain students and scholars are exempt from counting days for a period. Your visa category does not settle this.
OnlineWho: You
4
Check for an applicable tax treaty
The US has income tax treaties with around 70 countries. Arizona begins from federal adjusted gross income, so a federal treaty exclusion generally flows through to the state return — unlike California, which ignores treaties entirely. For a University of Arizona researcher or graduate student that is a meaningful difference between neighbouring states.
OnlineWho: You
5
Look at Arizona's tax credit programmes before you donate anything
Arizona offers dollar-for-dollar state tax credits for donations to qualifying charitable organisations, foster care agencies, public school extracurricular fees and private school tuition organisations. Within the published limits these reduce your Arizona tax bill by the full amount donated — you are choosing where a slice of your state tax goes rather than paying it. Very few states do this and almost no newcomer knows.
OnlineWho: You
6
File an FBAR if foreign accounts exceed $10,000
Aggregate foreign financial account balances above $10,000 at any point in the year trigger a FinCEN filing, separate from your tax return. An ordinary current account at home is often enough to cross it.
OnlineWho: You

Documents you’ll need

Form W-2 from each employer, issued by 31 January
Form 1099s for freelance, interest and investment income
Passport and travel history for the substantial presence day count
Foreign account statements for FBAR reporting
Receipts for Arizona credit-eligible donations, if claiming them

Things most newcomers don’t know

Tucson sets its own minimum wage and it is not the state's.

Proposition 206, passed by Tucson voters in November 2021, created a city minimum wage that reached USD 15.00 on 1 January 2025 and USD 15.45 on 1 January 2026, indexed to inflation each January and rising automatically to match any higher state or federal rate. Only Tucson and Flagstaff have their own floors in Arizona. Hourly workers moving from Phoenix get a raise for the same job, and an employer advertising the state rate inside the city limits is not complying.

Source: City of Tucson — Tucson Minimum Wage Act

Arizona's dollar-for-dollar tax credits let you direct where part of your state tax goes.

Donations to qualifying charitable organisations, foster care charities, public school extracurricular programmes and private school tuition organisations generate credits that reduce your Arizona tax bill by the full amount given, up to published limits. This is a credit, not a deduction — a $400 qualifying donation reduces tax owed by $400. Within the caps it costs you nothing and redirects money you were going to pay anyway.

Source: Arizona Department of Revenue — tax credits

The rental tax that used to appear on every Arizona lease was abolished in 2025.

Until the end of 2024 most Arizona cities charged a transaction privilege tax on residential rent, collected by the landlord and added to the monthly bill. State law removed it for long-term residential rentals from 1 January 2025. Older leases, older listings and older relocation guides still quote it. If a landlord is adding city rental tax to a tenancy of 30 days or more, question it.

Source: Arizona Department of Revenue — residential rental guidelines

Arizona does not observe daylight saving, which matters more than it sounds.

Tucson stays on Mountain Standard Time all year, so it shares a clock with Los Angeles from March to November and with Denver from November to March. For anyone working with an east coast or European team the meeting window shifts by an hour twice a year without your own clock changing, and every recurring invite accepted before the move quietly drifts. Fix the timezone on your calendar rather than the individual events. Note the exception inside the state: the Navajo Nation, in Arizona's north-east, does observe daylight saving.

Source: community-reported

Common mistakes to avoid

Not filing an Arizona A-4 and letting the employer apply a default withholding percentage.
Accepting Arizona's state minimum wage for work performed inside Tucson city limits.
Donating to charity without checking whether it qualifies for a dollar-for-dollar Arizona credit.
Accepting a lease that still adds city rental tax to a long-term residential tenancy.
Believing a filing extension also extends the payment deadline — it does not.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.