How to choose a tree service in Pennsylvania: insurance, credentials and red flags

Updated November 10, 2026 · KeystoneProGuide editorial team

What matters most when you hire someone to work on a tree?

Insurance comes first, because of what the work involves. Then credentials, a written contract, and a sense of how the company works.

Why is insurance the first question?

Because people get hurt doing this work, and some of them die. The U.S. Bureau of Labor Statistics counted 80 deaths of tree trimmers and pruners in 2023, and trees, logs and limbs were the main source of 79 deaths in the wider industry group that includes them. The Occupational Safety and Health Administration (OSHA) says falls and being struck by falling trees, limbs and tools are leading causes of death and serious injury for tree care workers, and that contact with power lines is a further hazard.

If a worker is injured on your property, the question of who pays becomes yours to worry about. The Tree Care Industry Association, the trade association of tree care companies, says that if a company has no insurance or is not a legal company, the homeowner could be held responsible as a contractor. Penn State Extension's Master Gardeners say much the same about unqualified operators: they "may not be insured, leaving you with the liability burden should things go wrong."

What insurance should a tree company have?

Two kinds, and you should see both.

• Liability insurance, for injury to other people and damage to property. Pennsylvania requires registered home improvement contractors to show the Attorney General at least $50,000 of personal injury cover and $50,000 of property damage cover.
• Workers' compensation, which covers the crew themselves. Pennsylvania's Department of Labor and Industry says an employer with even one employee who could be hurt at work in the state must insure its workers' compensation liability, including part-time workers and family members. Sole proprietors and general partners are among the people the law excludes, so a business run by its owner alone may not be required to carry it. If someone else will climb your tree, ask who employs them.

Penn State Extension advises asking to be shown proof of liability and workers' compensation insurance. The trade association says to ask for current certificates at the first meeting. Check the dates against the date of your job, and check that the business named on the certificate is the one you are hiring.

What does "certified arborist" mean?

It is a private credential, not a government licence. The International Society of Arboriculture (ISA), which runs the best-known certification, describes it as a "nongovernmental, voluntary process." ISA says a Certified Arborist has passed an exam on tree biology, diagnosis, maintenance and safety, must keep up continuing education, and must follow a code of ethics. ISA says the program is accredited by the ANSI National Accreditation Board. Those are the credentialing body's own statements about its own program.

Penn State Extension recommends using an ISA Certified Arborist where possible, and says a qualified arborist keeps up with safe techniques, has insurance and follows the ISA code of conduct. ISA's consumer site, TreesAreGood.org, lets you search for certified arborists by ZIP code, which is also a way to check a name you have been given.

No state licence for tree workers appears on the state's own lists; the details are in what Pennsylvania and its towns require. Some towns do set their own conditions, and the Tree Care Industry Association suggests asking your municipality whether it requires licensing for arborists.

Should the company be registered with the state?

Ask for a Pennsylvania home improvement contractor number and look it up on the Attorney General's contractor search, which lists "Tree services" among its types of work. The law's coverage of pure tree work is not spelled out, so a missing number is a question to ask, not proof of wrongdoing. The Attorney General also says registration is not an endorsement, recommendation or approval of a contractor's skill.

If the job includes spraying or injecting a tree, the company also needs a Pennsylvania pesticide business licence, which the Department of Agriculture says requires at least one certified applicator and proof of insurance.

What should the written estimate say?

Penn State Extension recommends at least two or three written bids and a written contract. Its list of what the contract should state:

• the trees, by type and location;
• what is being done to each: which branches, what size, how much;
• cleanup, disposal of debris, and what happens to firewood;
• start and completion dates;
• the total cost of the work;
• terms of payment, with payment after the work is finished to your satisfaction.

The Federal Trade Commission adds that the contract should carry the contractor's name, address, phone and licence number, and that all blank spaces should be filled in. Price comparisons are covered in what tree work costs.

How can you tell good pruning practice from bad?

Listen to what the company proposes. Penn State says reputable tree companies generally do not solicit door-to-door or list "topping" as a service, and suggests considering another firm if "topping" or "rounding over" appears in the paperwork. The Tree Care Industry Association says climbing spikes should be used only on a tree that is coming down, because spikes damage the tree.

Penn State lists signs of good pruning you can check on a company's past jobs: cuts made just outside the branch collar rather than flush with the trunk, no torn bark or spike marks, and no tree paint on the cuts.

What are the red flags?

The Federal Trade Commission's list of home improvement scam tactics fits tree work closely:

• knocking on your door because they are "in the area";
• pressing you to decide on the spot;
• asking for all of the money up front, or cash only;
• asking you to get any permits yourself.

Penn State's Master Gardeners add "limited-time" deals and say plainly: "Never pay in advance." The Pennsylvania Insurance Department warns that natural disasters draw dishonest solicitors, and says to be cautious of contractors with no company information on their vehicles.

Take your time where you can. Businesses that serve your area are on the tree services directory page.

Sources

1. Frequently Asked Questions: Home Improvement Contractor Registration, Pennsylvania Office of Attorney General
2. Census of Fatal Occupational Injuries News Release, 2023 Results, U.S. Bureau of Labor Statistics
3. Inspection Guidance for Tree Care and Tree Removal Operations, Occupational Safety and Health Administration
4. Workers' Compensation Compliance, Pennsylvania Department of Labor and Industry
5. Hiring a Tree Care Company, Tree Care Industry Association
6. Why Hire an Arborist?, International Society of Arboriculture (TreesAreGood.org)
7. ISA Certified Arborist, International Society of Arboriculture
8. Pruning Landscape Trees, Penn State Extension
9. When to Call an Arborist, Penn State Extension (Allegheny County Master Gardeners)
10. Home Improvement Contractor Registration, Pennsylvania Office of Attorney General
11. Home Improvement Contractor Search, Pennsylvania Office of Attorney General
12. How To Avoid a Home Improvement Scam, Federal Trade Commission
13. Pesticide Application Businesses, Pennsylvania Department of Agriculture
14. Natural Disaster Insurance Guide, Pennsylvania Insurance Department