Do tree services and arborists need a licence in Ontario?
Not province-wide. Skilled Trades Ontario classes Arborist (444A) as a non-compulsory trade, so no Certificate of Qualification is legally required to do tree work. Two licences can still apply: in Hamilton, a tree service company that prunes, removes or investigates a tree on your property must hold a City-issued Tree Cutting Service License, and anyone applying pesticides commercially needs an exterminator licence unless exempt. ISA credentials can be verified in ISA's Find an Arborist portal.[1],[2],[3],[4]
How to check
Search ISA's Find an Arborist portal by name or certification ID to verify an ISA-credentialed arborist; it replaced ISA's older Verify a Credential tool. In Hamilton, ask for the company's City-issued Tree Cutting Service License.[2],[4]
What Ontario's rules say
- Skilled Trades Ontario classes Arborist (444A) as a non-compulsory trade, so no Certificate of Qualification is legally required to do tree work. Skilled Trades Ontario[1]
- You can verify an ISA-credentialed arborist by name or certification ID in ISA's Find an Arborist directory, which replaced its older Verify a Credential tool. International Society of Arboriculture[4]
- In Hamilton, a tree service company that prunes, removes or investigates a tree on your property must hold a Tree Cutting Service License issued by the City. City of Hamilton[2]
- In Ontario, unless exempt, anyone who applies pesticides commercially on property they or their employer do not own needs a pesticide exterminator licence, valid for 5 years. Government of Ontario[3]
- In Toronto, injuring or removing a private tree 30 centimetres or more in diameter, measured 1.4 metres up the trunk, needs a permit under the City's Tree Protection By-law. City of Toronto[5]
Frequently asked questions
Does an arborist need a licence in Ontario?
No provincial certificate is required. Arborist (444A) is a non-compulsory trade, and compulsory trades are the ones that require a registered apprenticeship or a Certificate of Qualification to work legally.[1]
How do I verify an arborist's certification?
Search ISA's Find an Arborist portal by name or certification or recipient ID. It lists ISA-credentialed professionals and replaces ISA's legacy Verify a Credential tool.[4]
Does a tree service need a licence in Hamilton?
Yes. A tree service company you hire to prune, remove or investigate a tree on your private property must hold a valid Tree Cutting Service License issued by the City of Hamilton.[2]
Do I need a permit to remove a tree in Toronto?
For a private tree 30 centimetres or more in diameter, yes: injuring or removing it needs a permit under the City's Tree Protection By-law. Measure the diameter 1.4 metres up the trunk from the ground.[5]
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Sources
- Skilled Trades Ontario, Apprenticeship programs quick facts chart (Updated June 2026). Accessed October 19, 2026.
- City of Hamilton, Tree ownership and responsibilities. Accessed October 19, 2026.
- Government of Ontario, Pesticide licences and permits (Updated June 2, 2026). Accessed October 19, 2026.
- International Society of Arboriculture, Find an Arborist portal: FAQs (Revised January 2026). Accessed October 19, 2026.
- City of Toronto, When to apply for a tree or ravine permit. Accessed October 19, 2026.
This guide restates what each source says; it is not legal advice. Rules change — the linked source is the authority.
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