Seattle B&O Tax 2026: What Changed Under Seattle Shield

Seattle imposes its own business license tax—commonly called the Seattle B&O tax—separately from Washington State B&O tax. For tax year 2026, Seattle Shield changed the city framework enough that businesses should not rely on a 2025 threshold, rate table or return process without reviewing the new rules.

The most visible change is the jump in the annual taxable-revenue threshold from $100,000 to $2 million. But the threshold is only one part of the 2026 system. Businesses at or above the threshold can also use a separate annual standard deduction of up to $2 million, and Seattle increased the tax rates for every active classification.

Those changes can reduce or eliminate tax for many smaller businesses while changing the calculation for larger companies. They do not eliminate the need to determine Seattle-source income, maintain a business license when required, classify revenue correctly, or file a return when the city requires one.

What changed in Seattle B&O tax for 2026?

Seattle Shield took effect January 1, 2026. According to Seattle City Finance, the principal changes are:

• the annual B&O tax threshold increased from $100,000 to $2 million;
• a new annual standard deduction of up to $2 million became available to taxpayers that are subject to the tax;
• B&O tax rates increased for all active classifications; and
• new credits became available for specified comprehensive cancer centers and pediatric hospitals.

The practical impact depends on a company's Seattle taxable revenue before the standard deduction, the classification of that revenue, and any deductions or apportionment rules that apply. For service businesses, the calculation often starts well before the tax rate because the company first has to determine how much of its service income is apportioned to Seattle.

The $2 million threshold and $2 million standard deduction are not the same thing

This is the most important conceptual distinction in the 2026 rules. Seattle treats the threshold and standard deduction as separate steps.

For an annual filer with Seattle taxable revenue below $2 million after applicable general deductions, no Seattle B&O tax is due for the year. The business still files if required and reports the revenue that supports the zero-tax result.

If taxable revenue is at least $2 million, the business is subject to the tax and may apply the standard deduction. For example, a service business with $3 million of Seattle taxable revenue before the standard deduction would generally have $1 million remaining after a full $2 million standard deduction, before considering any other facts that affect the calculation. At the 2026 Service & Other Business Activities rate of 0.658%, $1 million of taxable amount would produce $6,580 of Seattle B&O tax.

The threshold answers whether the business is subject to the tax. The standard deduction answers how much taxable amount remains after the threshold has been met.

Seattle also specifies how the standard deduction is used when a business reports more than one classification: it is applied first to the classification with the highest tax rate, then to lower-rate classifications until the annual deduction is exhausted or taxable revenue reaches zero.

What are the Seattle B&O tax rates for 2026?

Seattle's current rate table applies for 2026 through 2032. The city lists the following active classifications and rates:

The rate is applied to the taxable amount in the applicable classification after deductions. A company may need more than one classification if it performs materially different business activities.

For professional-service firms, technology companies, consultants, accounting firms, architects, engineers and many other businesses whose activity is not taxable under another Seattle classification, Service & Other Business Activities is commonly relevant. Classification should still be determined from the actual activity rather than the company's industry label.

Does a business under the $2 million threshold still have to file?

Yes, in many cases. Seattle City Finance states that businesses under the 2026 $2 million B&O threshold are still required to complete and file their Seattle business license tax returns. A zero-tax result does not automatically remove the filing obligation.

Filing frequency is assigned by the city. Seattle notes that some businesses previously filing quarterly may move to annual filing because the threshold increased. For 2026, the first-quarter return for quarterly filers was due April 30, 2026, while a 2026 annual return is due April 30, 2027.

The business license tax certificate is also a separate issue from B&O liability. Seattle's 2026 licensing guidance states that a person without a place of business in Seattle can qualify for a small-revenue licensing exemption when annual Seattle gross revenue is $4,000 or less, subject to the city's conditions and any separate regulatory-license requirements. A company should not treat that narrow license exception as equivalent to the $2 million B&O threshold.

How does Seattle apportion service income?

For apportionable Service & Other Business Activities, Seattle generally uses a two-factor formula consisting of a payroll factor and a service-income factor. The two percentages are added and divided by two.

The service-income factor uses customer location. For business customers, Seattle's current rule generally looks first to where the services were ordered from, then to the customer's billing or mailing address if that location is unknown, and then to the customer's commercial domicile if neither is known. Different rules apply to nonbusiness customers and services requiring the customer's physical presence.

The payroll factor generally reflects employee compensation assigned to Seattle under the city's rules. Because service companies can have employees, customers and work activity in different cities, the resulting Seattle taxable revenue can differ materially from the amount recorded by a Seattle office or from the legal entity's total revenue.

A business that files more frequently than annually may also need to use prior-year factors for current-year reporting and reconcile when the actual annual factors become available. Seattle Director's Rule 5-047 and the city's return instructions should be reviewed for the particular filing pattern.

Seattle B&O tax is separate from Washington State B&O tax

Washington State and the City of Seattle both use gross-receipts-style business taxes, but they are separate systems with different thresholds, rates, sourcing rules, returns and administrative authorities.

A company can therefore owe Washington State B&O tax and have no Seattle B&O tax due, owe both, or have filing obligations in both systems with different taxable amounts.

For the state framework, see Washington B&O Tax and Washington B&O Tax Apportionment for Service Income.

A practical 2026 Seattle B&O review process

Why accounting structure matters more after Seattle Shield

The 2026 rules make the tax calculation more favorable for many businesses, but they also create a new reconciliation problem: the company needs enough city-level detail to support the threshold, deduction and classification calculations.

For multi-location or service businesses, a single “Seattle revenue” account is often not enough. The records should allow the company to distinguish customer location, employee payroll location, general deductions, classifications and the annual standard-deduction balance.

That accounting structure is especially important for groups operating in both Seattle and Bellevue because each city has its own B&O framework and the same revenue may need to be analyzed differently for each jurisdiction.

This article provides general information and is not legal or tax advice. The correct treatment depends on the facts, the applicable tax period and current city rules.