Key takeaways
- ISA certification attaches to a person, not to a company.
- The ISA describes certified arborists as people who have passed an exam covering all aspects of tree care.
- Verify the number on the ISA's site before relying on it.
- Certification is not a Nevada contractor license, and the Nevada State Contractors Board's consumer guide lists tree removal and trimming as work that does not need one.
- A credential does not replace insurance or a clear estimate.
Plenty of tree companies say 'certified' without saying who is certified. Knowing what the credential covers helps you ask a better question. Battle Born Tree Service has two ISA Certified Arborists on staff, and prints the number ISA Certified Arborist WE-11728A.
What does ISA Certified Arborist mean?
It means a person has qualified for and passed the certification program of the International Society of Arboriculture. The ISA says certified arborists are experienced professionals who have passed a comprehensive exam covering all aspects of tree care.
The credential is for individuals. A company should say 'we employ an ISA Certified Arborist', not 'we are an ISA certified company'. Battle Born says it has two on staff, and a certified arborist assesses every job before work begins.
How can you verify a certification number?
Ask for the arborist's name and number, then look them up on the ISA's verification page. If the person cannot give you a number, you have your answer.
ISA credentials also have to be renewed, so check that the status is current. The verification link is in the sources below, because it is an interactive page.
- Ask the company for the arborist's full name and certification number.
- Open the ISA verification page on treesaregood.org.
- Search by name or number and read the status.
- Check that the name matches the person who visits your property.
Does certification mean the company is licensed?
No. They are separate things. The Nevada State Contractors Board's consumer guide lists removal and trimming of trees and shrubs among work that does not require a contractor's license, so there is no contractor license number for tree work.
What a Nevada tree company can show is a Nevada business license. Battle Born prints Nevada Business License # 20131580674 and says it is licensed and fully insured. See our proof of insurance guide for how to confirm the insurance.
Why does certification matter for your tree?
Because the decisions on a mature tree, such as what to cut, what to leave and whether it can stay, depend on judgment as much as equipment. A trained arborist looks at structure, decay and surroundings before choosing a method.
The ISA also publishes a brochure on why topping is not an acceptable pruning technique; see why topping is not pruning.
What should you still ask a certified company?
Everything else. Ask about insurance, the scope of work, who will be on site, what is included in the estimate and how the cleanup is handled.
A credential tells you something about knowledge. It does not tell you what the price covers.
What does certification not tell you?
It does not tell you how a company prices, how fast it works or how it treats your property. It also does not make a company the right fit for every job; a small ornamental and a 90-foot cottonwood call for different crews.
Use the credential as one input. Pair it with a clear estimate, proof of insurance and a conversation about how the work will be done, and compare more than one company, as the ISA advises.
Sources
- International Society of Arboriculture, Trees Are Good: Why Hire an Arborist (PDF) (read October 17, 2026)
- ISA Trees Are Good: Verify an ISA Certified Arborist (listed October 1, 2026; interactive page, check it yourself)
- Nevada State Contractors Board: Choosing the Right Landscaper (read October 1, 2026)