Answer First: Before hiring a tree service, confirm four things: that an ISA Certified Arborist is doing or leading the work and you can verify the credential in the ISA directory; that they carry liability insurance and a current WSIB clearance certificate, which protects you if a worker is hurt; that they will handle any City of Toronto tree permit, which Chapter 813 requires for any private tree 30 cm or more in diameter at 1.4 m; and that they do not top trees, a discredited practice. Get the full scope in writing, and never pay in full before the work is done.
Tree work is the one landscaping job where hiring wrong can hurt someone or cost you a five-figure liability. A falling limb, an uninsured climber, an illegally removed protected tree, each is a real risk, and each is avoidable by asking the right questions first.
Are you an ISA Certified Arborist, and can I verify it?
This is the first question, because it is your best single signal of competence. ISA Certified Arborist — a tree-care professional certified by the International Society of Arboriculture, meaning they have met minimum knowledge and skill requirements and are held to a code of ethics and industry standards (ISA).
Do not just take their word for it. The ISA runs a public Find an Arborist directory where you can verify that a person actually holds a current credential, so ask for the certified arborist's name and check it yourself. Certification does not guarantee a perfect job, but its absence on a crew swinging chainsaws near your house is a real warning.
Quotable: An ISA Certified Arborist has met minimum knowledge and skill requirements and follows a code of ethics, and you can verify anyone's credential in the ISA's public directory. On a job with chainsaws near your house, that verification is worth the two minutes.
Do you carry insurance and a WSIB clearance?
Non-negotiable, both of them. You need to see liability insurance, which covers damage to your property or a neighbour's if something goes wrong, and proof of workers' compensation coverage for anyone on your property.
WSIB clearance certificate — a document confirming a contractor is registered with Ontario's WSIB and up to date on premiums and reporting, which protects you from liability if a worker is injured on your job (WSIB). It is valid for up to 90 days, so ask for a current one, not an old copy.
The reason this matters so much for tree work specifically is the injury risk. If an uninsured climber falls on your property, you do not want to be the one exposed, and the WSIB clearance is exactly the document that keeps that risk off you.
From the data: YardQuote ranks pros on verified review data, and the single most reliable pre-hire signal we see across every trade is a consistent, multi-year review history. A tree crew with years of reviews behind it has a reputation to protect; a brand-new company knocking after a storm does not.
Will you handle the City permit, and do you top trees?
Two questions that quickly separate professionals from cutters. First, the permit: under Toronto Municipal Code Chapter 813, you need a City permit to remove or injure any private tree measuring 30 cm or more in diameter at 1.4 metres above the ground, and the fines run from $500 to $100,000 per tree (Chapter 813). A real arborist knows when one is needed and handles or guides the application; a cutter removes the tree and leaves you holding the violation. The full permit process and cost are in tree removal permit cost in Toronto.
Second, topping. Topping — cutting a tree's main limbs back to stubs, a discredited practice that causes weak regrowth, decay and slow decline. A qualified arborist will not top a tree and will propose proper pruning or full removal instead.
If a company offers to top your tree, that alone is reason to look elsewhere, because it signals they are not working to current arboriculture standards.
What else should I get before work starts?
The scope in writing, references, and no full payment upfront. Get a written estimate that spells out exactly what is included, removal versus pruning, stump grinding, cleanup and haul-away, so there are no surprises. Ask for recent local references. And be especially careful after storms, when door-knocking crews pressure homeowners to decide immediately and pay in full before the work; a legitimate arborist will still put everything in writing rather than rush you.
The same caution applies to any trade, which is the whole point of knowing the contractor red flags before you sign. Tree and general yard work often sit with landscaping crews, so you can compare vetted pros on the Toronto landscaping cost page or in your area, such as landscaping in North York or Scarborough.
Want vetted local pros for tree and yard work? Request a quote and compare up to three side by side, so you can check certification and insurance before you choose. Your contact details only go to the one you pick.