The design of a potential statewide income tax for Washington centers on critical choices that will ultimately determine the tax’s effects on residents, businesses, and the state’s future. These key decisions include setting tax rates, defining which incomes are taxed or exempted, handling business income, and determining revenue allocation. While previous articles examined Washington’s absence of a personal income tax and outlined key arguments for and against it, this article focuses on how specific design decisions shape whether an income tax would strengthen or hinder the state’s economic and social well-being.
 

When analyzing state tax policy, a central decision is defining the tax rate structure. Lawmakers must choose between a flat tax, where all pay the same tax percentage on taxable income (e.g., 4 percent), and a progressive tax, which imposes lower rates on lower-income households and higher rates on higher-income households (e.g., 2 percent at the bottom and up to 8 percent at the top). Additionally, policymakers must determine which types of income are taxed, such as wages, investment income, business profits, and capital gains. Importantly, a broader tax base enables lower rates, while a narrower base typically requires higher rates to generate equivalent revenue.

 
Other essential choices include exemptions, credits, and handling business or corporate income. States may exempt Social Security or retirement income, or exclude income below a threshold. Tax credits can offset costs for families or low-wage earners. Lawmakers may partly exclude pass-through business income or apply lower rates to support hiring and investment, and decide whether to tax corporate profits at the business or individual level.

 
The core issue is how new tax revenue will be allocated. Directing income tax dollars to areas such as K-12 education, higher education, workforce training, transportation, public health, or local services could yield tangible benefits. If communities observe improvements in schools, roads, and public safety, public trust in the tax system may increase. Conversely, if the income tax merely replaces other taxes without noticeable advantages, residents and employers may question its value. For businesses, allocating tax revenue to workforce and infrastructure development could offset some of the tax's cost.

 
All these choices involve trade-offs that shape Washington’s business climate and quality of life. For example, higher tax rates or fewer exemptions could raise more revenue for public services but would increase taxpayer burdens and might discourage businesses from expanding or relocating to the state. On the other hand, more exemptions and credits could protect groups like small businesses or low-income residents, but may require higher rates for others or reductions in government spending. A simpler tax system is easier for taxpayers to understand and comply with, though it is less customized to the diverse needs of individuals and businesses. A more detailed system, while potentially fairer by addressing specific situations, can be harder to administer effectively.

 
Designing a statewide income tax goes beyond choosing a rate; it requires lawmakers to make targeted decisions that will decide whether such a tax advances or undercuts economic vitality, fairness, and community strength in Washington. An effective system can enhance tax fairness, provide stable funding for essential services, and foster long-term growth. In contrast, a poorly structured tax could raise costs, dampen investment, and erode public trust. The debate is not just about whether to implement an income tax, but how to design it so it delivers tangible benefits and strengthens communities statewide.

• This article was written with contributions from AI to organize the information and improve its readability.

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Washington adopted two important land division laws in 2025, which aimed to speed up housing production and make local reviews more predictable. One law updates how cities regulate “unit lot subdivisions.” The other creates a simple process for residential lot splits within cities. Together, they set clearer standards, shortened review steps, and informed cities when they must update their codes.

SB 5559: Clearer rules for unit lot subdivisions
SB 5559 adds detail to the 2023 law, which first required local governments to allow unit lot subdivisions. The new law narrows down the scope of who must comply. Only cities and towns in counties that plan under the Growth Management Act must adopt these rules. Counties and non-GMA jurisdictions are not required to do so.

The bill sets the timelines. Cities that owe a comprehensive plan update in 2027 must include unit lot subdivision provisions in that update. All other affected cities and towns must adopt the required regulations within two years of the bill’s effective date (May 20, 2025).

SB 5559 also adds definitions for “parent lot,” “unit lot,” and “unit lot subdivision,” and defines what “clear and objective” standards mean. It requires prominent informational notes on recorded plats, including the original application number and warnings regarding any limits on future development. Purchasers must be notified of the legal status of a unit lot subdivision by June 30, 2026.

The local review must be administrative. Cities cannot require pre-decision public hearings or design reviews beyond an administrative check, except where state law, such as the Shoreline Management Act, requires it. Review timelines in RCW 36.70B.080 apply, and neighbors within 250 feet must receive notice with instructions on how to submit comments. Critical areas and other protective regulations still apply.
 
HB 1096: A simple, administrative lot split inside cities

HB 1096 directs cities to create a straightforward process for splitting one residential lot into two, if certain conditions are met. The decision is made administratively by the planning director or a designee, using clear and objective standards. The lot split can be reviewed simultaneously with a residential building permit for either single-family or middle housing. Lots created under this process are exempt from the detailed middle housing requirements of RCW 36.70A.635.

The law lists specific conditions. Only one new lot may be created, both lots must meet the minimum size requirement, the parent lot cannot be the product of a prior split under this section, and the site must be in a residential zone. The applicant must propose a strategy to reduce renter displacement if a tenant is affected. Utilities must be available, and access and utility rights must be secured for the number of homes. Lots that are not buildable due to critical areas, shorelines, or similar limits do not qualify for this exemption.

Compliance timelines mirror those of SB 5559. Cities with a 2027 periodic update must include lot split provisions in that update. Other cities have two years from May 20, 2025. Local ordinances adopting these provisions are exempt from SEPA’s administrative or judicial appeals. The Department of Commerce will provide guidance to cities regarding implementation.

Why this matters

For local governments, these laws call for prompt code updates, standardized administrative reviews, and better public notice. For homeowners and builders, the changes open new paths to create additional homes on existing land while keeping reviews focused on clear and measurable rules. The result should be a faster, more predictable process that respects environmental and safety limits.

Washington is pushing for more housing by making land division simpler and clearer. SB 5559 strengthens the unit lot subdivision rules for GMA cities and towns. HB 1096 provides cities with a reliable administrative path to split residential lots when basic standards are met. Both laws set firm timelines and maintain protections for critical areas. To dive deeper into the details and citations, read the original MRSC article: https://mrsc.org/stay-informed/mrsc-insight/june-2025/subdivision-legislation. 
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