How to File LLC Taxes in Washington (2026)
A single-member Washington LLC reports its federal taxes on Form 1040 with Schedule C. A multi-member LLC files Form 1065. An S-corp election uses Form 1120-S, and a C-corp election uses Form 1120.
Washington has no state income tax. Your LLC still files an Excise Tax Return with the Washington Department of Revenue. Federal self-employment tax and Washington's B&O tax both apply no matter which classification you pick.
Quick Summary
- File with two agencies this year. The IRS handles your federal return, and the Washington Department of Revenue handles your Excise Tax Return.
- Washington's B&O tax applies to gross receipts, not profit. Budget for it even in a slow year, since a loss doesn't erase what's due.
- Elect S-corp or C-corp status only after a CPA models the costs. Washington's excise tax obligations stay the same either way.
Washington LLC Tax Summary
Here's how each Washington LLC classification maps to its federal form, state filing and due dates. You'll see your full filing picture at a glance.
| LLC Type | Federal Form | State Form | Filed With | Filing Deadline & Tax Rate |
|---|---|---|---|---|
| Single-member LLC | Schedule C (Form 1040) | None (no state income tax) | N/A | April 15 federal deadline. No state income tax. |
| Multi-member LLC | Form 1065 | None (no state income tax) | N/A | March 15 federal deadline. No state income tax. |
| S-Corp election | Form 1120-S | None (no state income tax) | N/A | March 15 federal deadline. No state income tax. |
| C-Corp election | Form 1120 | None (no state income tax) | N/A | April 15 federal deadline. No state income tax. |
| Business & Occupation (B&O) tax | N/A | Excise Tax Return | Washington Department of Revenue | Monthly (25th), quarterly (month-end), or annual (April 15), assigned by liability |
How Washington LLCs Are Taxed
The IRS taxes your LLC based on its federal classification instead of its state of formation. A single-member LLC is a disregarded entity by default.
A multi-member LLC is a partnership by default, and either one can elect corporate treatment if it makes sense for the business.
Each classification instead owes the business and occupation (B&O) tax under state law [1]. That tax falls on gross receipts instead of profit.
The B&O rate depends on your business classification. Retailing sits at 0.471%, and manufacturing and wholesaling both sit at 0.484%.
Service businesses pay 1.5% to 2.1%, based on how much they gross each year. See our guide to filing LLC taxes for the federal basics.
File the Excise Tax Return by the 25th of the following month if you're a monthly filer, by the end of the month after the quarter if quarterly, or by April 15 if you file annually.
1. Single-member LLC: Form 1040 (Schedule C)
Single-member LLCs are disregarded entities by default, so the IRS taxes you as if you're a sole proprietor. You report the LLC's income and expenses on Schedule C. That flows into your personal Form 1040, due April 15.
You still register your LLC for a Washington business license and UBI number, then file the Excise Tax Return once you're set up. Processing takes about 10 business days online, or up to six weeks if you apply by mail.
2. Multi-member LLC: Form 1065
Multi-member LLCs are partnerships by default. The LLC files Form 1065 by March 15 for a calendar-year partnership. It also gives each owner a Schedule K-1 for their share of the profit. Each owner then reports that income on their own Form 1040.
3. S-Corp election: Form 1120-S
An LLC can elect S-corp treatment by filing Form 2553 with the IRS. Once approved, the LLC files Form 1120-S annually, due March 15 for a calendar-year corporation. It also issues Schedule K-1s to its owners.
The election can cut self-employment tax once profit is steady enough to support a reasonable salary. Washington doesn't tax the election itself, so weigh the added payroll costs against the B&O tax you'll owe either way.
4. C-Corp election: Form 1120
Filing Form 8832 with the IRS elects C-corp treatment. Tax then applies at the corporate level instead of passing through to owners. The corporation files Form 1120 annually, due April 15 for a calendar-year filer.
This structure fits larger LLCs that want to retain earnings or offer corporate benefits. It rarely pays off for a small LLC once you count the added filing and accounting work.
Washington income tax rate for tax year 2026
Washington adds a 9.9% tax on individual income above $1,000,000 starting January 1, 2028. This follows Senate Bill 6346 [2].
The first returns are due in 2029. Confirm the current rate on the Department of Revenue's income tax page before you file.
Federal Taxes Washington LLC Owners Pay
Any LLC owner who takes profit out of the business may owe federal tax on it. That's true no matter how Washington treats the LLC at the state level.
1. Self-employment tax
A member who receives profit from the LLC owes self-employment tax at 15.3%. That rate covers Social Security and Medicare taxes. Washington has no separate state self-employment tax.
2. Quarterly estimated tax payments
If you expect to owe $1,000 or more in federal tax for the year, the IRS wants quarterly estimated payments due April 15, June 15, September 15 and January 15 of the following year.
Washington has no matching state estimated-tax form to file alongside these federal payments. Set money aside anyway, since the B&O tax comes due on its own schedule regardless of your federal payments.
Other Washington Taxes That May Apply
Beyond the B&O tax, a few other Washington taxes kick in depending on what your LLC does and whether it has employees.
1. Employer taxes
If your LLC has employees, register with the Washington Employment Security Department for unemployment insurance tax and with the Washington Department of Labor & Industries for workers' compensation coverage.
ESD sets your unemployment rate each year based on your payroll and claims history, so plan for it as a separate line item from your B&O tax.
2. Sales and use tax
Washington charges destination-based sales tax. The rate depends on where your customer takes delivery. If your LLC sells taxable goods or services, register with the Washington Department of Revenue before your first sale.
Look up the exact combined state and local rate for any address with the DOR's Washington Tax Rate Lookup Tool. Do this before you set your price.
3. Industry and local taxes
Some industries carry their own Washington excise taxes on top of the B&O tax. Examples include the hazardous substance tax, the litter tax and taxes on tobacco, vapor and spirits sales.
What Is Deductible for a Washington LLC
Because B&O is a gross-receipts tax, you can't deduct payroll, materials or other business costs to lower what you owe.
A few specific B&O deductions exist for narrow cases like bad debts and certain nonprofit activities. General operating expenses aren't among them.
Federal deductions still apply to your income tax return, including the qualified business income deduction under Section 199A. That deduction comes from the IRS rather than Washington.
References:
- https://app.leg.wa.gov/rcw/default.aspx?cite=82.04
- https://dor.wa.gov/taxes-rates/income-tax
FAQs
How Often Does a Washington LLC File the Excise Tax Return?
How often a Washington LLC files the Excise Tax Return depends on its tax liability. Annual liability of $1,050 or less files annually. Liability from $1,051 to $4,800 files quarterly. Anything higher files monthly.
Do Washington LLCs Pay Tax on Profits Kept in the Business?
Yes, Washington LLCs pay tax on profits kept in the business because the B&O tax is due whether you distribute or retain earnings. There's no separate state tax on retained earnings itself.
Is There a Washington Pass-Through Entity Tax for LLCs?
No, there's no Washington pass-through entity tax for LLCs. The state has no personal income tax, so there's no SALT-cap workaround to elect into.
Does Washington Have a Franchise Tax for LLCs?
No, Washington doesn't levy a separate franchise tax on LLCs. The B&O tax functions as the state's main entity-level tax instead, based on your business classification rather than net worth or capital.
