How to Start a Solar Installation Business in Washington: No Solar License, the L&I Electrical Contractor License Is the Gate

Washington does not issue a solar license. That sounds like good news until you realize what it means: no single credential says "solar installer," so the state regulates your work through the trades it touches. For most solar installers, the trade that matters most is electrical. If you want to know how to start a solar installer business in Washington, the practical answer is to form the business, register it with the state, and obtain the Department of Labor and Industries (L&I) electrical contractor license before anyone wires a panel.

This guide covers the order that works, the fees we could verify, and the mistakes that cost new installers time and money.

Disclaimer: This article is general information about Washington business formation and licensing. It is not legal or tax advice. Solar work involves electrical, structural, and utility rules that change and depend on your specific project. Talk with a Washington attorney and a CPA before you form your entity, and confirm current requirements directly with L&I, the Department of Revenue, and your local building department.

What You Need Before You Start

Gather these items before you file anything:

• A business name you want to use, checked against the Secretary of State business search
• A Washington street address for your registered agent (PO boxes and private mailbox addresses are not accepted)
• An account in the Corporations and Charities Filing System (CCFS) if you form an LLC or corporation
• A $4,000 surety bond for the electrical contractor license
• A designated master electrician or administrator, plus a plan to employ certified electricians
• A Unified Business Identifier (UBI) number, issued through the state Business License Application
• Insurance quotes for general liability and L&I industrial insurance (Washington's workers' compensation system)
• Your serving utility's interconnection requirements and incentive rules

Here is what the core filings cost, using the figures we could verify:

Item	Cost	Agency
LLC Certificate of Formation with Initial Report	$180	Secretary of State
Expedited service (generally processed within three business days)	$100 per entity	Secretary of State
Name reservation (held for 180 days)	$30	Secretary of State
LLC annual report (late filing total)	$70 ($95 if late)	Secretary of State
Business License Application processing fee (to open a business)	$50, plus endorsement fees	Department of Revenue
Trade name registration (each name)	$5, plus processing fee	Department of Revenue
Electrical contractor license, per 24 months (initial application or paper renewal / online renewal)	$353.90 / $306.20	L&I
Electrical contractor bond	$4,000	L&I
Construction contractor registration (RCW 18.27)	$150.20	L&I
Construction contractor bond	$30,000 general or $15,000 specialty	L&I

Step 1: Understand Why the Electrical License Is the Gate

Washington's electrical rules cover PV wiring, so every solar installation that connects to a building's electrical system needs work performed under an L&I electrical contractor license and by certified electricians. The rules also list specialty electrical licenses, and solar is not among them (WAC 296-46B-920). The general electrical contractor license is the safe route. Ask L&I whether the residential specialty fits a particular job, and get the answer in writing if you can.

Solar work can touch other trades too:

• Roof penetrations and mounting may require a construction contractor registration under RCW 18.27.
• Solar heating systems fall under the HVAC/R and plumbing specialties, not the electrical license.
• Building-integrated PV panels may be placed by people who are not electricians (WAC 296-46B-690(4)). This is a narrow exception. Confirm with L&I how it applies to your job before you rely on it, and do not assume it covers the wiring.
• EV charger work on public works requires EVITP certification starting January 1, 2026 (RCW 19.28.285).

Step 2: Choose Your Legal Structure

Your structure determines whether you file with the Secretary of State at all. A sole proprietorship or general partnership does not file with the Secretary of State. It may still need a state business license and any trade name registration, but the formation filing is skipped. An LLC or corporation files a formation document with the Secretary of State, which separates the entity from your personal finances when you run it properly.

Washington does not tax corporate income or personal income from wages. Instead, the state uses a business and occupation (B&O) tax, which is a gross receipts tax with more than 50 activity classifications. Many installers are surprised that there is no deduction for labor or materials. About 54 cities also levy their own B&O taxes, which the Department of Revenue does not administer. Ask a CPA which structure makes sense for your expected revenue, payroll, and equipment purchases.

Step 3: Choose and Protect Your Business Name

An LLC name must include Limited Liability Company, Limited Liability Co., L.L.C., or LLC. It must be distinguishable from every other business name on record with the Secretary of State. Under RCW 23.95.305, it also cannot include the words bank, banking, banker, trust, cooperative, or certain combinations of industrial and loan, building, savings, loan, home, association, and society.

If you need time to file, you can reserve the name for 180 days for $30 through the Secretary of State fee schedule. If you plan to operate under a name other than your legal name, such as "Evergreen Solar Works," you will also need a trade name registration. Trade names are registered with the Department of Revenue, not the Secretary of State or your county.

Step 4: File the Formation Document

File your Certificate of Formation with Initial Report through CCFS for $180. Expedited service costs $100 per entity and is generally processed within three business days. The Secretary of State does not publish a standard turnaround for online filings, so do not schedule your first installation or your bank account opening around an assumed date. Build in a buffer of at least several weeks.

Once the LLC exists, you owe an annual report of $70 each year. It is due by the last day of the month in which the LLC was originally formed, and you can file it up to 180 days early. A late filing carries a delinquency fee, bringing the total to $95. Put the due date on your calendar the day you form the company.

Step 5: Appoint a Registered Agent

Every LLC or corporation must designate and maintain a registered agent in Washington under RCW 23.95.405. The agent can be commercial, registered with the Secretary of State, or noncommercial. The agent must consent to serve, supply an email address, and maintain a physical street address in Washington. You can serve as your own agent if you have a qualifying address, but many owners who work in the field use a commercial agent so that legal papers reach someone during the workday. Changing the registered agent or registered office carries no fee.

Step 6: Register With the Business Licensing Service

The Department of Revenue's Business Licensing Service issues the state Business License Application and your UBI number. You almost certainly need it for solar work. It is required if you plan to hire employees within 90 days, sell anything subject to sales tax, earn $12,000 or more in gross income per year, or need city or state endorsements. Corporations and LLCs must file with the Secretary of State before submitting the Business License Application.

The processing fee is $50 to open a business, plus separate endorsement fees. Online applications take about 10 business days. If city or state endorsements need approval, add two to three weeks. Mailed applications can take up to six weeks, so file online when you can.

Two more items belong on this step:

• Trade name: register at dor.wa.gov for $5 per name. Adding a trade name to an existing business carries a $10 processing fee instead of the $50 opening fee.
• B&O classification: ask the Department of Revenue which classification fits your installation and service income. Then check whether your city levies a local B&O tax. Sales tax at the state rate of 6.5% may apply to certain sales, so confirm with the Department of Revenue how it treats your contracts before you quote prices.

Step 7: Obtain the L&I Electrical Contractor License

This is the core licensing step. Under RCW 19.28.041 and WAC 296-46B-909, an electrical contractor license requires a UBI, a $4,000 bond, and a designated master electrician or administrator who oversees the business. You must also employ certified electricians to perform the electrical work. The initial application costs $353.90, and the license covers 24 months. Renewals completed fully online cost $306.20.

Build the application around the people, not just the paperwork. The designated master electrician or administrator must be qualified, and your electricians must hold the certifications the rules require. Confirm exact experience, exam, and certification requirements with L&I, because this article does not list them. Confirm the residential specialty question with L&I too, since your typical job may fall under it.

Step 8: Register for Roof Work and Other Trades

If your crews fasten racking to roofs, check whether you need a construction contractor registration under RCW 18.27. The registration fee is $150.20. Depending on the registration type, you must post a $30,000 general or $15,000 specialty bond. Many solar companies hold both the electrical license and the construction registration, because roof work and wiring usually happen on the same job.

Also check permits. Cities and counties generally require building and electrical permits for solar arrays. Your local building department can tell you which permits apply and how long reviews take. Health district permits are rarely relevant to solar, but confirm this with your jurisdiction if you also plan to offer related services.

Step 9: Set Up Employer Accounts and Insurance

Once you hire, you must register with L&I for industrial insurance and with the Employment Security Department for unemployment insurance. Confirm the current fees and reporting schedules with each agency, since this article does not list them. Get general liability coverage in place before you sign customer contracts, and ask your insurer whether roof work and electrical work need separate endorsements.

Step 10: Confirm Utility and Incentive Rules

Net metering rules and incentives vary by utility, and they change. Contact your serving utility before you price a single job. Ask how it handles interconnection applications, inspection timing, and export credits. Then check whether any incentive is still available for the customers you plan to serve. Do not promise a customer a specific incentive or savings figure until the utility confirms it in writing.

Common Mistakes to Avoid

• Selling solar contracts before the license is issued. Taking deposits or scheduling installs before your electrical contractor license is active creates legal and refund problems.
• Assuming a solar specialty exists. Ask L&I which license fits your work. Do not rely on a general answer you read online.
• Using a PO box as the registered agent address. The state does not accept PO boxes or private mailbox addresses.
• Forgetting the annual report. A late LLC annual report adds a delinquency fee, and the total rises to $95.
• Operating under a trade name without registering it. Trade names go through the Department of Revenue, not the Secretary of State or your county.
• Ignoring city B&O taxes. The state B&O tax is only part of the picture, and about 54 cities add their own.
• Treating roof work as a side task. Mounting may require a separate contractor registration and bond.

Expected Results

Licensing usually takes longer than new owners expect. A reasonable plan can allow several months from formation to a fully licensed, insured company, and that estimate depends on how quickly you file, how fast endorsements are approved, and how quickly L&I reviews your electrical contractor application. Owners who complete the filings in order may find they can take their first paid jobs sooner, but no guaranteed timeline exists. Installers who skip steps often lose more time to rework and delays than they save.

Your revenue outcome depends on your market, your pricing, your crew, and the incentives available in your utility territory. This article does not promise any income, savings, or return for customers or owners. If you want advising on the business side, the Washington Small Business Development Center offers help to new owners. Confirm which services are available and their cost before you schedule them.

Final Checklist

1. Confirm the license path with L&I, including the residential specialty question.
2. Choose your structure and check the name in the Secretary of State business search.
3. Reserve the name if you need time, then file the Certificate of Formation through CCFS.
4. Appoint a registered agent with a physical Washington address.
5. Register with the Business Licensing Service and get your UBI number.
6. Apply for the L&I electrical contractor license and post the $4,000 bond.
7. Register for construction contractor work if your crews will mount on roofs.
8. Set up L&I industrial insurance, unemployment insurance, and general liability.
9. Confirm your utility's interconnection rules and incentive status.

This article is informational, not legal or tax advice. Before you commit to a structure, a bond, or a customer contract, consult a qualified Washington attorney and a CPA, and verify every figure with the agency that administers it.