NSNexus by State

Washington vs Idaho Sales Tax: 9.51% vs 6.03%, Nexus 2026

Updated

Reviewed by Nexus by State research team using official state tax sources. Last reviewed .

Compare Washington and Idaho sales tax rates: Washington shows a 9.51% combined state and average local rate with a $100,000 economic nexus threshold, while Idaho shows 6.03% with a $100,000 threshold. This guide focuses on seller sales-tax obligations rather than personal income-tax returns.

MetricWashingtonIdaho
Economic nexus threshold$100,000$100,000
Transaction thresholdNoneNone
State rate6.50%6.00%
Avg. local rate3.01%0.03%
Combined state + local9.51%6.03%
Marketplace facilitatorYesYes
Effective since2020-01-012019-06-01

Which state is easier for sellers?

For low-revenue sellers: nexus triggers first in both states because of its threshold. If you cross that first, you register there first.

On rate: Idaho is friendlier for customers with a combined state + local rate of 6.03% vs 9.51%.

Neither state has a transaction-count trigger — only the dollar threshold matters.

Washington — nexus note

Washington sales tax nexus and economic nexus threshold: $100,000 in gross receipts sourced or attributed to Washington in the current or prior year (eff. 2020-01-01). The transaction-count threshold was eliminated when this unified threshold took effect. Crossing the threshold registers a remote seller for both retail sales tax AND Business & Occupation (B&O) tax — Washington classifies remote-seller revenue under the Retailing B&O classification, and a "No Local Activity" deduction is available when the seller has no in-state physical B&O nexus. Marketplace facilitator law (RCW 82.08.0531; marketplace facilitator defined at RCW 82.08.010(15)) applies the same $100,000 Washington-receipts threshold to marketplaces — Amazon, Etsy, eBay, and Walmart collect and remit Washington sales tax on third-party transactions they facilitate, and have provided monthly Washington-sales reports to their sellers since 2019-07-01. Direct-to-consumer Washington sales you make outside any marketplace continue to count toward your own $100,000 economic-nexus calculation.

Idaho — nexus note

Idaho sales/use tax nexus and economic nexus threshold: effective June 1, 2019, an out-of-state retailer without a physical presence in Idaho must collect Idaho sales tax once its combined Idaho sales exceed $100,000 in the current or previous calendar year. Idaho uses a sales-only threshold — no transaction-count test. The threshold counts all Idaho retail sales — taxable, exempt, wholesale, and sales facilitated through third-party marketplaces — and marketplace-facilitated sales still count toward a seller's own threshold even when the marketplace collects the tax. A marketplace facilitator without Idaho physical presence must register and collect once the combined total of its own sales plus the sales it facilitates for retailers exceeds $100,000. Idaho's state sales tax rate is 6%, with limited local resort-city and auditorium-district taxes. Idaho State Tax Commission source data last retrieved 2026-06-14.

What to do next

Use the nexus calculator to check exactly which of Washington and Idaho you've already triggered. Then read each state's full guide:

Washington overview →Idaho overview →

Frequently asked questions

Which state has the lower sales tax nexus threshold, Washington or Idaho?
Both Washington and Idaho publish the same economic nexus dollar threshold of $100,000, so a remote seller would reach each state's published threshold at the same level of in-state sales. These are the thresholds published by each state's tax authority as of 2026-06-14; confirm against the official source before registering.
Do both Washington and Idaho have marketplace facilitator laws?
Yes. Both Washington and Idaho have marketplace facilitator laws, so marketplaces such as Amazon, Etsy, and eBay collect and remit sales tax on the sales they facilitate in both states. Direct-to-consumer sales you make outside a marketplace remain your own responsibility once you cross each state's threshold. Verified 2026-06-14.
Which has the lower sales tax rate, Washington or Idaho?
Idaho has the lower combined state and local sales tax rate at 6.03%, compared with 9.51% in Washington. These are the statewide base rate plus the average local rate; the exact rate depends on the customer's delivery address. As of 2026-06-14.
Do I need to register for sales tax in both Washington and Idaho?
It depends on where you cross each state's economic nexus threshold (or have physical presence there). Washington's published threshold is $100,000, and Idaho's is $100,000. You generally register in a state only once you cross its threshold, so you may have an obligation in one, both, or neither. Run the nexus calculator with your actual sales and confirm with each state's official source. Thresholds as of 2026-06-14.
When did economic nexus take effect in Washington and Idaho?
Washington's economic nexus rule took effect on 2020-01-01, and Idaho's took effect on 2019-06-01. Both stem from the 2018 South Dakota v. Wayfair Supreme Court decision, which let states require remote sellers to collect once an economic threshold is met.

More sales tax comparisons

Selling into more than two states? Compare Washington and Idaho against other major markets for nexus thresholds, rates, and marketplace facilitator rules.

More Washington comparisons

More Idaho comparisons

    Sources

    date_retrieved: Washington 2026-05-26 · Idaho 2026-06-14