If I live in Idaho but work in Washington, how am I taxed?

If you live in Idaho and work in Washington, Idaho taxes your paycheck. Idaho residents owe Idaho income tax on all of their income, no matter which state it was earned in, and Washington has no personal income tax to credit against it. So the answer to “does Washington and Idaho have reciprocity” is that there’s nothing to reciprocate — Washington never taxed your wages in the first place. You file one state return, in Idaho.

How the tax mechanics actually work

Three things matter in practice:

• Idaho taxes residents on worldwide income. Your Washington wages go on your Idaho return like any other wages. The Idaho State Tax Commission publishes current rates and brackets — we won’t quote them here because they change.
• Idaho gives a credit for income taxes paid to other states, but since Washington charges none, the credit is zero. You pay the full Idaho tab.
• Your Washington employer probably won’t withhold Idaho tax. Many won’t, since they have no Idaho obligation. That means you may need to file quarterly estimated payments with Idaho or face an underpayment penalty in April. Ask your payroll department first; some larger employers will withhold Idaho tax voluntarily. A CPA is worth the fee the first year you set this up.

The reverse commute is the one people chase for tax arbitrage: live in Washington, and your Washington wages face no state income tax at all. (Idaho-source wages are still taxed by Idaho even for Washington residents, so the arbitrage only works if the job itself is on the Washington side.)

So why would anyone live in Idaho and work in Washington?

Because income tax is one line item, not the whole picture. Idaho generally carries lower property taxes, offers a homeowner’s exemption on a primary residence, has a lower sales tax, and has no estate tax. Washington makes up its zero income tax with higher sales and gas taxes and a graduated real estate excise tax paid by sellers. For some households — especially those with modest wage income or income that Idaho exempts, like Social Security — the Idaho side still pencils out. We walk through the full comparison in Washington vs Idaho taxes explained and the longer WA vs ID tax breakdown.

Housing prices complicate it further. As of June 2026, Post Falls listed at a median asking price of $577,900 versus $465,000 in Spokane Valley and $449,000 in Spokane — and 46% of Post Falls listings were under contract that month, the strongest demand reading on the corridor. The Idaho side costs more per square foot but property taxes on it run lower. The math is genuinely household-specific, which is why we point people to the cheaper-side question before they commit to a zip code.

The commute itself is the easy part

This border crossing is ordinary. Post Falls to Liberty Lake is about 10 minutes on I-90; Post Falls to downtown Spokane runs roughly 25–30 minutes outside of peak traffic. Thousands of people cross the line for work every weekday in both directions. There’s no toll, no checkpoint, nothing administrative — the only thing that changes at the state line is which government taxes what.

We write contracts on both sides of that line every month, so if you’re deciding between Post Falls and Spokane Valley with a Washington paycheck in hand, reach out and we’ll run both scenarios with you. For your specific tax numbers, bring a CPA into the conversation — this page is general information, not tax advice.