Quick answer: Checking a Tree Contractor — The crew that answers the phone is the crew that climbs the tree: locally based, insured, and working to the industry standards rather than to whatever the last job allowed. That matters most where the work is delicate — over a roof, beside a wire, or on a slope where the wood has to be lowered rather than dropped.
Field note. What we see is that the questions worth asking are the same on every property: who is climbing, what happens to the wood, and what the tree looks like in five years — so we answer those before we talk about dates.
On the other hand, credentials are a floor rather than a guarantee: what a tree gets is the judgment of the person in it, which is why we keep the same small crew on this coast.
Tree work is one of the few trades where an uninsured operator can put a lien on your house. The check takes ten minutes and it is the highest-value ten minutes in the whole transaction.
Document one: the contractor’s licence
In California, a contractor performing tree work above a certain value must hold a contractor’s licence, and it can be verified in the state’s own lookup by licence number. The number should be on the quote, not just in a conversation.
What to check: the number exists, the name matches the business, and the classification is appropriate. A licence that belongs to a different company, or one that is suspended, is the finding that ends the conversation.
Document two: liability insurance
Liability insurance covers damage to your property. If a limb goes through a window and the operator is uninsured, the claim is against your own homeowner’s policy, and the insurer will ask whether you checked.
Ask for a certificate of insurance naming the coverage and the limits, and then call the insurer to confirm the policy is current. A certificate is a piece of paper; confirmation is the fact.
Document three: workers’ compensation
This is the one people skip and the one that matters most. If a worker is injured on your property and the contractor does not carry workers’ comp, the injured worker can claim against you.
Ask for the certificate, and confirm it. In California an employer is required to carry it, and a contractor with employees who does not is a contractor who is either misclassified or uninsured.
What else is worth asking
Whether the person doing the climbing holds a current certification — the ISA arborist credential or an equivalent — because the certificate is evidence of training rather than a legal requirement.
Whether the quote is written and what it includes: the method, the disposal, the stump, and the site restoration. A verbal quote is a quote that changes.
And whether the crew will be employees or subcontractors. A subcontractor arrangement means the insurance question has to be asked again about the subcontractor.
What a good quote contains
The scope, in plain language. The method — felled, rigged or crane. What is removed from site. Whether the stump is included and to what depth. Whether the site is raked and restored. The price, the payment terms, and the start date.
And, ideally, the arborist’s reasoning: why this intervention rather than another. A quote that explains itself is a quote from someone who has thought about the tree.
The red flags
A price well below the others, which usually means no insurance and no disposal. A request for cash with no paperwork. A recommendation to top a tree, or to remove a healthy one without a stated reason. A crew that arrives without the equipment the quote described.
The one question that filters fastest
Ask for the three certificates before the quote is discussed. An operator who has them sends them without hesitation. An operator who does not will change the subject, and that is the answer.
The related question of what the work should cost and why is here.