King County, Washington business licensing guide
Last updated: August 1, 2026 · Next review: December 1, 2026
Business licensing in King County has several layers. Washington state, King County, Seattle, and the other cities do different jobs.
Your first task is to find the legal jurisdiction for the exact business address. A Seattle mailing address may be inside Seattle, another city, or unincorporated King County. That one fact changes where you check local licenses, zoning, building rules, and city taxes.
Bottom line
King County does not issue one general county business license to every business. The county says its own business licenses are limited to listed regulated activities in unincorporated King County, which means land outside city limits.
If your business is in Seattle, Bellevue, Kent, Renton, Redmond, Federal Way, Kirkland, Auburn, Shoreline, or another city, check that city for the local license, local tax, zoning, sign, building, fire, and home-business rules.
Most businesses should also check the Washington Department of Revenue. Its Business Licensing Service can issue a state business license and UBI number, set up tax accounts, register trade names, and add many city or state endorsements. Read our Washington business license guide for the state-wide process.
Quick start: use this order
- Confirm the exact jurisdiction. Use the King County property research tools. Do not rely only on the mailing city or ZIP code.
- Describe the business in plain words. Include what you sell, where work happens, whether customers visit, whether food is handled, and which cities you travel into.
- Check Washington registration. Use the Washington Business License Application if a registration trigger applies.
- Check the local layer. Contact Seattle or the correct city. For an unincorporated address, use King County Permits.
- Check activity permits before opening. Food, construction, alcohol, cannabis, transport, childcare, professional work, street vending, and public events can need separate approval.
- Save every approval and renewal date. Keep the license, UBI, tax account letters, zoning answer, permits, inspection records, and renewal notices together.
First, find the right local government
King County contains Seattle and many other incorporated cities. It also contains unincorporated communities. Local business rules follow legal boundaries, not postal labels.
Use the county’s property tools to confirm whether the exact parcel is inside a city. If it is inside city limits, the city normally handles the local business license and land-use questions. If it is outside every city, King County Local Services is the local government.
Do this before signing a lease
Ask the planning or zoning office whether your exact use is allowed at the address. A state license, UBI number, LLC filing, or city tax account does not make a prohibited land use legal.
For a simple explanation of the documents people often mix up, see business license vs. LLC vs. DBA vs. seller’s permit.
How the licensing layers work
| Government layer | What it may handle | Main place to check |
|---|---|---|
| Federal | EIN, federal taxes, and permits for a small group of regulated activities | IRS EIN page and the federal agency for the activity |
| Washington state | Business License Application, UBI, tax registration, trade names, state endorsements, employer setup, and professional or industry licensing | Washington Department of Revenue and the correct state agency |
| King County | Limited regulated business licenses in unincorporated areas, county zoning and permits, food permits, and business personal property reporting | King County Local Services, Public Health, and King County Assessor |
| Seattle or another city | Local business license, local B&O or other taxes, zoning, home occupation rules, signs, building, fire, vending, and local regulatory licenses | The city business license, finance, planning, building, and fire offices |
| Private rules | Lease, HOA, insurance, marketplace, payment processor, or platform requirements | Your contract, landlord, insurer, or platform |
Washington state business license and tax steps
Washington’s Business Licensing Service is part of the Department of Revenue. The application can create a state business license, assign a Unified Business Identifier called a UBI, register trade names, open tax accounts, and add many city and state endorsements.
When the state application is required
DOR lists several registration triggers. These include needing a city, county, or state endorsement; using a name other than the owner’s full legal name; planning to hire employees within 90 days; selling taxable products or services; having gross income of at least $12,000 a year; or owing a DOR-administered tax or fee.
If you form an LLC or corporation, the entity filing is a separate step. Start with the Washington Secretary of State business registration page, then complete the DOR steps that apply. An LLC still may need business licenses. See why LLCs still need licenses and permits.
Trade names, often called DBAs
Washington usually uses the term trade name. Register a trade name through DOR’s trade name process. DOR currently lists a $5 fee for each trade name, plus the Business License Application processing fee.
A trade name does not create a separate legal entity. It also does not replace a trademark search, city license, zoning approval, or professional license.
Processing time and renewals
DOR says online applications take about 10 business days. City or state endorsements can add two to three weeks. Mailed applications can take up to six weeks. Check the current Business License Application processing fees before paying.
Most city and state endorsements renew each year. DOR says it sends a notice in the month before the endorsement expires. Renew by the listed expiration date and submit any required documents. Use the state renewal guidance rather than guessing from the original issue date.
King County rules for unincorporated areas
King County’s own general business licensing role is narrow. The county business license page says a county license is needed only when both of these are true:
- The activity is one of the regulated business types listed by King County.
- The business is in unincorporated King County.
Listed categories include certain amusement activities, charitable solicitation, junk businesses, massage or bathhouse businesses, pawn or secondhand activities, shooting ranges, theaters, and other regulated operations. Use the county page for the current list and application form for the exact activity.
Completed county business license applications are submitted to PermitServices@kingcounty.gov. The county says incomplete applications are not accepted. After screening, the applicant receives instructions for online payment. King County Permits can be reached at 206-296-6600 for the licenses and permits it handles.
Zoning still applies to every unincorporated business
Even when no special county business license is required, all businesses in unincorporated King County must follow zoning rules. Check the allowed use before adding customer visits, commercial vehicles, outdoor storage, signs, equipment, or a change in building use.
A home business may not need a special county business license unless it is regulated, but it still must follow home occupation rules. Our home occupation permit guide explains the difference between a zoning approval and a general business license.
Building, land-use, mechanical, and fire permits
King County Permits handles land-use, building, mechanical, and fire regulatory and operating permits for unincorporated areas. Check permits before remodeling a storefront, changing occupancy, adding cooking equipment, installing a sign, storing hazardous materials, or opening an event space.
Business personal property reporting
Business equipment and other taxable personal property are a separate county tax matter. King County says property used in business as of January 1 must be reported, and the filing deadline is April 30. The King County eListing page explains online filing. The Personal Property team lists 206-296-5126 for questions.
Payment scam warning: King County says its staff will not call and ask for your credit or debit card details. Use the invoice and official payment instructions sent by the county.
Seattle and other King County cities
There is no single city license that covers all of King County. A business based in one city may also need to register in another city where it performs work.
Seattle
Seattle says anyone doing business in the city must have a Seattle business license tax certificate, also called a general business license in FileLocal. The certificate renews each year by December 31. Seattle accepts online applications and renewals through FileLocal and also provides mail forms.
Seattle’s city tax system is separate from Washington state taxes. Effective January 1, 2026, Seattle raised its B&O tax threshold to $2 million. A business below the threshold may owe no Seattle B&O tax, but the city says it still must file and report annual gross revenue. Check the Seattle business tax page for current filing rules and classifications.
Seattle home businesses must also follow local land-use rules. The city’s home business rules focus on keeping the business from disturbing the neighborhood. For a full local walkthrough, see our Seattle business license guide.
How selected cities route applications
| City | Current local route | Important note |
|---|---|---|
| Seattle | FileLocal or city mail form | Annual business license tax certificate; separate city tax filings may apply. |
| Bellevue | Bellevue business licensing and FileLocal | Check the city’s business-location and gross-income rules. Regulatory licenses can have separate renewals. |
| Kent | Kent business license page and FileLocal | Kent says businesses operating in the city need a city license and a Washington state license. City B&O tax is separate. |
| Renton | Renton business licensing and FileLocal | The city license is in addition to state registration. |
| Redmond | Redmond business licensing through Washington DOR BLS | Redmond uses a city endorsement printed on the Washington state business license. |
| Other cities | Washington DOR city endorsements or the city’s own system | Check the city where the business is located and every city where work is performed. |
The official FileLocal participating-city list includes these King County cities: Auburn, Bellevue, Des Moines, Kent, Lake Forest Park, Renton, Seattle, and Shoreline. Other cities may use DOR’s Business Licensing Service or a direct city process.
What to check for your operating model
| How you operate | Checks that often matter | Best first local question |
|---|---|---|
| Home-based | Home occupation rules, visits, employees, signs, inventory, deliveries, vehicles, noise, lease, and HOA rules | Is this activity allowed at my exact residential address? |
| Online seller | DOR tax registration, trade name, sales tax, home zoning, inventory storage, customer pickup, and marketplace records | Does my home activity require local licensing or zoning review? |
| Mobile service | Licenses or endorsements in each city served, local B&O taxes, parking, right-of-way, and activity permits | Do I need a nonresident or traveling-business license in this city? |
| Storefront or office | Zoning, building use, tenant improvements, fire review, signs, accessibility, and certificate or occupancy rules | May I use this unit for this exact business before I sign the lease? |
| Food business | Health plan review, food permit, food worker cards, commissary, fire, grease, waste, zoning, and local business license | Which plan review and operating permit apply before construction or opening? |
| Contractor or trade | DOR registration, L&I contractor registration or trade certification, bond, insurance, city licenses, and job permits | Which state registration and city endorsement apply to this work? |
Home-based and online businesses
Do not describe a business only as “online.” Tell the local office whether you store inventory, receive frequent deliveries, meet customers, use a garage, park work vehicles, employ helpers, or create noise. See our guides on running a business from home and online business license rules.
Mobile work in several cities
A cleaner based in unincorporated King County may work in Seattle, Bellevue, and Redmond. The home address controls the home-business and county zoning layer, but each work city can have its own license or tax rule. Check DOR city endorsements, FileLocal, and each city page before assuming one license covers the whole county.
Extra permits that depend on the activity
Restaurants, caterers, food trucks, and other food businesses
Public Health – Seattle & King County food business permits cover many restaurants, caterers, commercial commissary kitchens, grocery stores, school cafeterias, and mobile food units. New or remodeled mobile food businesses must submit plans before construction, remodeling, or a change of ownership.
The Public Health Permit Center handles food permit and plan-review applications. It lists 206-263-9566 for the downtown Seattle office and 206-477-8050 for the Bellevue/Eastgate office. A food truck may also need a city license, fire approval, property permission, and a street-use permit. Read our food truck permit guide.
Cottage food is different from a restaurant or ordinary home kitchen business. Check the Washington State Department of Agriculture cottage food program and our cottage food business guide.
Contractors and building trades
Washington Labor & Industries registers construction contractors and licenses or certifies several trades. Its contractor registration page says applicants must register the business with DOR, obtain the required bond or assignment of savings, buy liability insurance, submit the application, and pay the current fee. City licenses and job permits may still be required where work is performed.
Seattle regulated activities and public-space use
Seattle requires extra regulatory endorsements or licenses for certain activities. Use the Seattle business regulations directory for the current list. A vendor using a public street or sidewalk should also check Seattle vending permits. A private-property location may still need zoning, owner permission, health approval, and fire review.
Fees, timing, deadlines, and renewals
- Washington application: The processing fee varies by filing purpose. Endorsement and trade-name fees can be added.
- Washington processing: DOR estimates about 10 business days online, plus two to three more weeks when endorsements need approval. Mail can take up to six weeks.
- Seattle renewal: Renew the Seattle business license tax certificate each year by December 31.
- State and city endorsements: Most renew annually by the expiration date shown on the notice.
- King County personal property: Report business personal property used as of January 1 by April 30.
- Activity permits: Health, building, fire, contractor, and regulatory permits can have separate fees and renewal dates.
Budget rule: Do not plan only for a “business license fee.” Your real opening cost may include state processing, city registration, zoning review, plan review, inspections, building work, signs, food permits, bonds, insurance, and professional licensing.
Common mistakes
- Assuming Seattle rules cover all of King County. Each city and the unincorporated county have different systems.
- Using the mailing city as proof of jurisdiction. Confirm the parcel and city boundary.
- Stopping after getting a UBI. A UBI is not zoning, health, fire, building, or professional approval.
- Thinking an LLC replaces licenses. An LLC is a legal structure, not permission to operate.
- Signing a lease before zoning review. The intended use may be prohibited or may require expensive changes.
- Ignoring cities where mobile work occurs. A home-city license may not cover work in Seattle or another city.
- Building a food truck or kitchen before plan review. Public Health may require approval before construction.
- Missing separate city tax filings. Seattle, Bellevue, Kent, Renton, and other cities may have tax returns apart from state DOR filings.
- Paying a caller who claims to be the county. Use official invoices, portals, and agency contact pages.
Call or email script
Use this wording
Hello. I am planning a [business type] at [exact address]. The business will be [home-based / mobile / storefront / online / food-related]. It will involve [customers, employees, inventory, deliveries, equipment, vehicles, food, signs, or other activity].
Can you confirm whether this address is inside your city or in unincorporated King County? Which business license, city endorsement, tax account, zoning approval, home occupation approval, building or fire permit, health permit, or activity license should I check before I open?
Write down the date, office, person or department, exact permit names, application links, fees, renewal dates, and any other office you were told to contact.
About BusinessLicenseGuide.com
BusinessLicenseGuide.com explains U.S. business licenses, permits, registrations, and tax accounts in plain English. We are not a government agency, law firm, CPA firm, or filing service. We use official sources so readers can find the correct office and ask better questions before they pay or open.
Related business license guides
Start with the closest next-step guides, then explore other BLG location and licensing resources.
Best next guides
Explore more BLG guides
Frequently asked questions
Does King County require a general business license for every business?
No. King County says its own business licenses apply only when a business is in unincorporated King County and is one of the regulated business types listed by the county. Most businesses must still check Washington state registration and the city where they are located or work.
How do I know whether my address is in Seattle, another city, or unincorporated King County?
Use King County property research tools and confirm the jurisdiction for the exact parcel. A mailing address or ZIP code is not enough. If the property is inside a city, that city usually handles local licensing and zoning. If it is outside city limits, start with King County Local Services and King County Permits.
Do I need both a Washington state business license and a Seattle business license?
Many businesses do. Washington's Business Licensing Service handles the state business license, UBI number, tax registration, trade names, and many endorsements. Seattle separately requires a business license tax certificate for businesses doing business in the city and has its own tax filing system.
Where do I register a DBA in King County?
Washington usually calls a DBA a trade name. Register it through the Washington Department of Revenue's Business Licensing Service. A trade name does not create an LLC or corporation and does not replace a city license, zoning approval, or industry permit.
Can I run a business from home in unincorporated King County?
Possibly. King County says a home business does not need a special county business license unless it is a regulated activity, but it must follow home occupation zoning rules. Check customer visits, employees, signs, storage, deliveries, vehicles, noise, and any private lease or HOA rules.
Who issues food business permits in Seattle and King County?
Public Health – Seattle & King County issues many local food business permits and reviews plans for restaurants, caterers, commissary kitchens, grocery stores, mobile food units, and other retail food operations. Some activities, including cottage food and certain wholesale food work, are handled by the Washington State Department of Agriculture.
Does a UBI number prove that my location is approved?
No. A UBI number identifies the business in Washington's state system. It does not prove that zoning allows the use, that building or fire work is approved, or that health and professional permits are complete.
Do mobile businesses need a license in every King County city where they work?
They may. Contractors, cleaners, photographers, vendors, consultants, entertainers, and other mobile businesses should check each city where they conduct business. Some cities use Washington DOR city endorsements, some use FileLocal, and some have additional local tax or permit steps.
Disclaimer
This guide is for general information only. It is not legal, tax, accounting, insurance, employment, zoning, safety, or professional advice. Rules, fees, forms, portals, office names, phone numbers, and deadlines can change. Your requirements depend on the exact address, business activity, ownership, workers, products, services, and cities where you operate. Confirm important details with the official agency or a qualified professional before filing, paying, signing a lease, building, or opening.
Update notes
Reviewed August 1, 2026. This update verifies the county’s limited licensing role, Washington DOR application timing, Seattle’s annual license renewal, Seattle’s 2026 B&O threshold change, FileLocal city routing, King County personal-property reporting, and current food and contractor permit sources.