Seattle STR tax entity comparison: sole proprietorship, S-corp, and LLC structures

The way most Seattle STR owners file taxes — as individuals, reporting income on Schedule E — is the right structure for most situations. But as STR income grows, and particularly for owners who qualify as materially participating in an active STR trade or business, the entity structure question has real tax and financial planning implications.

This article compares the three most relevant structures for Seattle STR owners: sole proprietorship (or disregarded single-member LLC), S-corporation, and multi-member LLC taxed as a partnership. It is not a recommendation to restructure — it is a framework for understanding when the question is worth asking your CPA.

This article provides general educational information only and is not tax or legal advice. All entity and tax decisions should be made with a licensed CPA and attorney.

Key takeaways

• Most Seattle STR owners operate as de facto sole proprietors — income flows to Schedule E on their personal return, with no self-employment (SE) tax on net rental income. This is accurate and correct for passive rental income.
• If your STR qualifies as an "active trade or business" under IRS rules (average stay ≤ 7 days AND you materially participate), net income may be subject to self-employment tax — roughly 15.3% on the first ~$168,600 of net income (2024 figure; adjusts annually). This is where entity planning becomes relevant.
• An S-corp election allows you to pay yourself a "reasonable salary" from STR income (subject to payroll taxes) and take remaining profits as an S-corp distribution (not subject to SE tax). This split can reduce SE tax meaningfully at higher income levels.
• The S-corp structure adds significant administrative overhead: separate payroll, officer salary requirements, Form 1120-S filing, state registration. The math generally doesn't work below ~$40,000–$60,000 annual net STR income.
• Washington state has no personal income tax, which simplifies the state-level analysis compared to high-income-tax states like California or New York.

How STR income is taxed by default

For a standard Seattle STR where the owner does not materially participate, rental income is passive income. It flows through Schedule E on your personal return and is subject to federal income tax at your marginal rate — but not to self-employment tax (15.3% on net earnings). This is the tax treatment most STR owners have, and for passive rental income, it's efficient.

The SE tax question arises when two conditions are both met:

1. Average guest stay is 7 days or fewer: This is the STR-specific tax rule from IRS Revenue Ruling 93-32 and subsequent guidance. Properties with an average stay of 7 days or fewer are not treated as passive rental activities — they're treated as active business income. This applies to virtually all Airbnb and VRBO listings in Seattle, where average stays are typically 3–5 nights.
2. You materially participate: You meet one of the IRS's seven material participation tests (most commonly: you spend more than 500 hours/year on the activity, or more than 100 hours and more than any other individual).

If both conditions are met, your STR income may be characterized as active business income — subject to SE tax. This is why material participation is both a tax advantage (you can offset W-2 income with STR losses) and a potential tax cost (SE tax on net profits). It's a two-sided coin, and the right tax structure around it depends on your income level.

Structure comparison

Structure 1: Sole proprietorship / disregarded single-member LLC

What it is: The default. If you own your STR personally or through a single-member LLC without an S-corp election, income flows through to your personal return on Schedule E.

Tax treatment: Federal income tax at marginal rate. If passive, no SE tax. If active (7-day average AND material participation), SE tax applies to net profits.

Administrative overhead: Minimal. Schedule E, record-keeping, potential Form 4797 on sale. No separate entity returns unless you have an LLC (Washington requires an annual LLC report and fee).

Best for: Owners with passive STR income (no material participation), or active STR owners with net income below $40,000 where SE tax savings from restructuring don't outweigh administrative costs.

Structure 2: LLC with S-corporation election

What it is: A single-member LLC that elects to be treated as an S-corporation for tax purposes (Form 2553). The LLC itself is the legal entity; the S-corp election determines federal tax treatment.

Tax treatment: You pay yourself a "reasonable salary" from STR net income. That salary is subject to payroll taxes (employer and employee share of Social Security and Medicare). Profits above the salary are distributed as S-corp distributions — not subject to SE tax.

The SE tax math at different income levels:

Compare to sole proprietorship where SE tax applies to the full net amount. At $100,000 net, sole prop SE tax: $14,130. S-corp with $50K salary: $7,650. Savings: $6,480. Annual S-corp administrative cost: $1,500–$3,000.

Administrative overhead: Payroll (quarterly deposits, W-2s, 940/941 filings), Form 1120-S federal return, Washington state S-corp registration, officer salary documentation, separate business bank account and bookkeeping. Add $1,500–$3,000/year in accounting and payroll services.

The breakeven point: S-corp election saves SE taxes when the tax savings exceed the additional administrative cost. As a rough heuristic: if annual net STR income subject to SE tax exceeds $50,000–$60,000, the S-corp election is worth modeling with your CPA. Below $40,000, the administrative overhead typically exceeds the tax savings.

Best for: Active STR owners (7-day average, material participation) with net income above $50,000 annually, particularly those in higher marginal tax brackets where maximizing the salary/distribution split has the greatest impact.

Structure 3: Multi-member LLC taxed as a partnership

What it is: A multi-member LLC (owned by two or more people — spouses, partners, family members) defaults to partnership tax treatment. Files Form 1065; partners receive K-1s reporting their share of income.

Tax treatment: Pass-through to each partner's personal return. Each partner's share of active STR income may be subject to SE tax if the partnership qualifies as an active trade or business. Each partner can also make an S-corp election for their share if structured appropriately.

Relevant scenarios:

• Spouses who co-own an STR property and both want to claim material participation (relevant for the real estate professional exception under one spouse's qualification)
• Investment partners who share ownership and want pass-through treatment with clear documentation of each partner's basis and distributions
• Family LLC structures for estate planning combined with STR ownership

Administrative overhead: Form 1065 annual partnership return, K-1 issuance to all partners, Washington state annual report. More complex than sole proprietorship, though typically less overhead than S-corp due to no payroll requirement.

Best for: Co-ownership situations, family estate planning involving STR assets, or investment partnerships with multiple owners.

Washington state considerations

Washington has no personal income tax, which eliminates one of the primary drivers of entity structuring in states like California or New York. The entity comparison in Washington focuses primarily on federal SE tax savings and the administrative cost to achieve them.

Washington does impose:

• Business and Occupation (B&O) tax on STR gross revenue (typically under the service/other activities classification). This applies at the entity level — LLC, S-corp, or sole proprietor — and is not eliminated by entity restructuring.
• LLC annual report fee ($60–$200 based on revenue tier).
• S-corp registration requirements with the Washington Secretary of State.

None of these create a strong Washington-specific incentive to choose one structure over another — the federal SE tax analysis drives the decision.

The one question to ask your CPA

Before any entity restructuring conversation, determine whether your STR income is actually subject to SE tax under your current filing. Many STR owners assume they are paying SE tax when they are not — because their STR income is passive (no material participation) and therefore not subject to SE tax regardless of entity structure.

The question: "Is my current STR income being reported as subject to self-employment tax, and if so, at what annual amount?" If the answer is no, entity restructuring doesn't solve an SE tax problem you don't have. If the answer is yes and the amount is above $50,000 annually, the conversation is worth having.

Related reading: Offsetting W-2 taxes with short-term rentals and LLC vs. personal ownership for your Seattle STR.