Do You Need an Arborist License in Washington?

Last updated: October 2, 2026

Washington does not issue an arborist license — but do not read that as an open field, because tree work here is contracting by statute. RCW 18.27.010 puts performing tree removal services directly into the legal definition of a contractor. That single clause pulls a tree service into the Contractor Registration Act, and with it a surety bond, a general liability policy with L&I named on it, and registration before you take work. The state also runs workers compensation itself, so that piece cannot be bought from a private carrier at all.

What Washington Actually Requires

• No arborist license — Washington issues none and has no arborist board. ISA certification is voluntary here.
• ★ Contractor registration with Labor & Industries, because RCW 18.27.010 includes “performing tree removal services” in the statutory definition of a contractor.
• A surety bond: $30,000 for general contractors, or $15,000 for specialty contractors. An assignment of savings can stand in place of the bond.
• General liability insurance of at least $200,000 in public liability and $50,000 property damage, or $250,000 combined single limit.
• L&I listed as a certificate holder on that liability policy — the state wants to be told directly if it lapses.
• The registration fee of $150.20.
• Workers compensation through the L&I state fund if you have employees. Washington is monopolistic — there is no private market for it.
• A WSDA pesticide applicator license if you will apply pesticides for hire.

What It Costs

Item	Cost	Notes
Contractor registration fee	$150.20	Paid with the application to L&I
Surety bond	$30,000 / $15,000	General contractor / specialty contractor. You pay a premium on the bond, not the face value; an assignment of savings is an alternative
General liability insurance	$200,000 + $50,000	Public liability and property damage, or a $250,000 combined single limit. L&I must be a certificate holder
Workers compensation	L&I state fund only	Quarterly premiums by hours worked and risk class — no private carrier can write it in Washington
WSDA pesticide applicator license	See WSDA schedule	Only if you spray, inject or treat for hire
Washington LLC	$180	Certificate of formation on the Secretary of State’s form; expedited service adds $100

Coming From Another State

Is there an arborist license to transfer into Washington?

No — Washington does not license arborists, and your ISA Certified Arborist credential is issued by the International Society of Arboriculture rather than by a state, so it travels with you untouched.

But as established above, tree removal is contracting by statute in Washington — so what you are really transferring is a contracting position, and there the answer is more interesting than a simple yes or no.

The reciprocity Washington has is about workers’ comp, not licensing

Washington maintains reciprocal agreements with eight states covering workers’ compensation coverage. They let an employer bring employees temporarily into Washington from a reciprocal state without purchasing workers’ compensation insurance from L&I. The states are:

Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah and Wyoming.

Now the carve-out, and for a tree business it is the whole point:

The Montana and Nevada reciprocal agreements do not include construction work. If your Montana or Nevada employees are performing construction work in Washington, you must report their hours to Washington L&I.

Read that against what this page has already established. Tree removal in Washington is contracting by statute. So a Montana or Nevada crew coming over the border to take down trees is doing construction work, falls outside the reciprocal agreement, and its hours must be reported to L&I — even though a crew from Idaho, Oregon or Utah on the same job may be covered by reciprocity. Two crews, same work site, different obligations, decided entirely by which state they came from.

If you are running work across the Washington border, that is the sentence to check your own situation against before you assume your home-state coverage travels.

The contractor registration itself does not reciprocate

The workers’ compensation agreements above are about coverage, not credentials. Work done in Washington that requires contractor registration must be reported to L&I, and there is no equivalent published route that converts another state’s contractor registration into a Washington one. You register in Washington, and as covered above the bond comes before the chainsaw.

One practical note for the paperwork: unless you are a sole proprietor with no employees, you must have an Employer Identification Number, and the contractor registration application and its supporting documents go to an L&I office. The contractor registration line is 360-902-5226 — worth a call before you mobilize a crew, particularly if you are coming from Montana or Nevada.

Tree Removal Is Contracting by Statute — So the Bond Comes Before the Chainsaw

Most states that do not license arborists simply leave tree work alone. Washington took a different route: rather than build an arborist board, it wrote tree work into the contractor statute and let the existing machinery do the job.

The clause is short and it is decisive. The definition of “contractor” in RCW 18.27.010 lists, among construction, alteration, repair, roofing and siding work, “performing tree removal services”. There is no threshold, no residential-only qualifier and no argument to be had about whether cutting down a tree improves real estate. If you remove trees for money in Washington, you are a contractor, and an unregistered contractor is working illegally no matter how good the work is.

What registration actually costs you is the bond and the policy, not the fee. The fee is $150.20. The real items are a surety bond — $30,000 for a general contractor, $15,000 for a specialty contractor — and a general liability policy of at least $200,000 public liability and $50,000 property damage, or a $250,000 combined single limit. Note that the bond is not money you hand over; you pay a premium for it, and what you pay depends on your credit and history. An assignment of savings can be used instead of a bond if you would rather tie up cash than buy a surety.

One detail on the liability policy is easy to skim past and expensive to get wrong: L&I must be listed as a certificate holder. That is not a formality. It means the state is notified directly by your insurer about the status of the policy, so a lapse is not something you can quietly fix before anyone notices — the regulator finds out from the carrier.

The general-versus-specialty choice is worth thinking about before you file. A specialty contractor bond is half the general contractor bond, which makes it the cheaper door. The trade-off is scope: a specialty registration limits you to the trade you selected and does not let you subcontract outside it. A tree service that only removes, prunes and grinds may be perfectly served by specialty registration. One that wants to take on stump-to-patio jobs, retaining walls or drainage as part of the same contract will hit the limit quickly.

And workers compensation here is not a shopping decision at all. Washington is one of the few monopolistic states: workers compensation comes from the L&I state fund, and no private carrier writes it. If you employ anyone you enroll with L&I and pay quarterly premiums based on hours worked and risk classification — and tree work carries a high risk classification, which is exactly what you would expect from a trade that combines chainsaws with height. Do not budget for it as though you can shop the market, because you cannot. Your general liability policy is a separate purchase and covers a different thing entirely: the customer’s roof, not your groundworker’s back.

How to Get Licensed, In Order

1. Accept that you are a contractor — RCW 18.27.010 settles it, so plan around registration rather than looking for a way round it.
2. Choose general or specialty registration. Specialty halves the bond to $15,000 but locks you to one trade with no outside subcontracting.
3. Get the surety bond, $30,000 or $15,000 as applicable, or arrange an assignment of savings instead.
4. Buy the general liability policy at $200,000 public liability and $50,000 property damage, or $250,000 combined single limit.
5. Have your insurer list L&I as a certificate holder — registration is not complete without it.
6. File the application with the $150.20 fee.
7. Enroll with L&I for workers compensation if you will have employees. There is no private alternative in Washington.
8. Add a WSDA pesticide applicator license if you will spray or inject.
9. Register the business entity first, because the bond and the insurance must be issued in the exact business name.

Staying Licensed

Contractor registration has to stay continuously valid, and the two things that most often break it are the bond and the liability policy rather than the paperwork. Because L&I is a certificate holder on your general liability insurance, the state learns about a lapse from your insurer — so letting cover slide between carriers, even briefly, is visible. Keep the bond and the policy in the exact business name on the registration; a mismatch after a name change is a common and avoidable problem. If you employ people, L&I workers compensation premiums are quarterly and calculated on hours worked in your risk classification, so they move with your payroll rather than sitting flat. And if your work widens beyond the trade you registered for, revisit whether a specialty registration still covers what you are actually selling.

Frequently Asked Questions

Does Washington require an arborist license?

No. Washington issues no arborist license and has no arborist board. But that does not mean tree work is unregulated — RCW 18.27.010 includes performing tree removal services in the statutory definition of a contractor, so a tree service must register as a contractor with the Department of Labor and Industries before it can legally work or advertise.

What do I need to register as a contractor in Washington?

A surety bond, a general liability insurance policy, and the registration application. The bond is $30,000 for general contractors and $15,000 for specialty contractors. The liability policy must be at least $200,000 in public liability and $50,000 property damage, or $250,000 combined single limit. L&I must be listed as a certificate holder on the liability insurance, and the registration fee is $150.20.

Is tree removal really considered contracting in Washington?

Yes, and it is written into the statute rather than left to interpretation. The definition of contractor in RCW 18.27.010 expressly includes performing tree removal services alongside construction, alteration, repair, roofing and siding work. That is unusual — most states leave tree work outside their contractor statutes entirely.

Can I buy workers compensation from a private insurer in Washington?

No. Washington is one of a small number of monopolistic states where workers compensation is provided through the state fund at Labor and Industries rather than by private carriers. If you have employees, you pay L&I premiums based on hours worked and risk classification — you cannot substitute a private workers comp policy, and general liability cover is a separate thing entirely.

Tree work sits alongside our full guide to starting a landscaping business in Washington, and the wider guide to starting a business in Washington. Or see how every state handles tree work in our arborist license requirements by state guide.

Does Washington have contractor license reciprocity for tree work?

No. Work done in Washington that requires contractor registration must be reported to L&I, and there is no published route converting another state’s contractor registration into a Washington one. What Washington does have is workers’ compensation reciprocity with Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah and Wyoming, which lets employers bring employees temporarily into the state without buying L&I coverage.

Does the Washington workers comp reciprocity cover tree work crews?

It depends which state they come from. The Montana and Nevada reciprocal agreements do not include construction work, so Montana or Nevada employees performing construction work in Washington must have their hours reported to L&I. Because tree removal is contracting by statute in Washington, a Montana or Nevada tree crew falls outside the agreement even though a crew from Idaho, Oregon or Utah on the same job may be covered.

Sources

Source	What It Covers
RCW 18.27.010 — definitions	The statutory definition of a contractor, which expressly includes performing tree removal services
Washington L&I — register as a contractor	The $30,000 general and $15,000 specialty bond amounts, the $200,000 / $50,000 or $250,000 combined single limit liability minimums, the requirement that L&I be a certificate holder, and the $150.20 registration fee
Washington Secretary of State — LLC certificate of formation	The $180 filing fee and the $100 expedite charge on the current form
Washington L&I — Out-of-State Employers and Out-of-State Workers	The eight reciprocal states for workers compensation coverage and the exclusion of construction work from the Montana and Nevada agreements
Washington L&I — Application for Construction Contractor Registration	The registration application, its supporting documents and the employer identification number requirement