NAICS Codes and WSIB Classification in Ontario (2026)
TL;DR
WSIB does not set a premium rate for each NAICS code — it sets one rate per class or subclass under its Rate Framework. In 2026, construction splits into six subclasses (per $100 of insurable earnings): G1 Residential Building $2.18, G2 Infrastructure $1.72, G3 Foundation/Structure/Exterior $3.55, G4 Building Equipment $1.54, G5 Specialty Trades $2.15, G6 Non-residential Building $1.61. Roofing, framing and masonry all sit in G3; electrical and plumbing in G4; drywall, painting and finish carpentry in G5. Premium = insurable earnings × class rate ÷ 100, capped at $121,700 per worker for 2026. Construction coverage is mandatory — including for sole proprietors and partners on their own labour earnings.
How does WSIB use your NAICS code?
The North American Industry Classification System is maintained by Statistics Canada with its counterparts in the U.S. and Mexico. It gives every business a 6-digit code for its primary activity: a framing contractor is 238130, an electrician is 238210, a general-freight trucker is 484110. WSIB takes that predominant activity and maps it to one of roughly 34 classes and subclasses under its Rate Framework, and the class — not the individual NAICS code — carries the premium rate, expressed as dollars per $100 of insurable earnings. The rate reflects the real, pooled cost of injuries across every employer in that class over the last several years, so classes with frequent, severe claims cost more. In 2026 the all-Ontario average rate is $1.23 per $100, the lowest in more than 50 years.
What are the 2026 WSIB construction rates?
Construction is Class G, and it splits into six subclasses. These are the published 2026 class rates (2025 shown for comparison):
| Subclass |
Covers (NAICS) |
2026 / $100 |
2025 / $100 |
| G1 Residential Building | Home builders (2361) | $2.18 | $2.32 |
| G2 Infrastructure | Road, bridge, sewer/water (237) | $1.72 | $1.74 |
| G3 Foundation / Structure / Exterior | Concrete, steel, framing, masonry, roofing, siding, glazing (2381) | $3.55 | $3.52 |
| G4 Building Equipment | Electrical, plumbing, HVAC (2382) | $1.54 | $1.49 |
| G5 Specialty Trades | Drywall, paint, flooring, tile, finish carpentry, site prep (2383, 2389) | $2.15 | $2.15 |
| G6 Non-residential Building | Commercial, institutional, industrial (2362) | $1.61 | $1.57 |
According to WSIB's published 2026 premium rates, foundation, structure and exterior work (G3) is the most expensive construction subclass at $3.55 per $100 — that band holds the falls-from-height and structural-collapse claims. Note the catch that surprises people: a roofer, a framer and a bricklayer all pay the same G3 rate, because WSIB groups all of NAICS 2381 into one subclass. There is no separate "roofing rate" any more; the old per-rate-group system was replaced by the Rate Framework in 2020.
Why do so many trades share one rate?
Because WSIB prices risk at the class level, then adjusts for you individually. Grouping every foundation/structure/exterior trade into G3 spreads the cost of a bad claim across a bigger pool, which keeps rates stable. What separates two G3 framing crews is not the class rate — it's their own claims record, applied through the Rate Framework's risk bands (below). So the class rate in this tool is your starting point, not your final number.
Worked example: what a roofer actually pays
Say you run a roofing crew with $400,000 of insurable earnings for the year. Roofing is NAICS 238160, which maps to construction subclass G3 at $3.55. Your base premium is:
$400,000 × $3.55 ÷ 100 = $14,200 (before risk-band adjustment)
Now watch the classification swing. If that same $400,000 belonged to a finish-carpentry shop — NAICS 238350, subclass G5 at $2.15 — the base premium is $8,600. That's a $5,600 per-year difference driven purely by which subclass the work sits in. If WSIB audits and finds crews on roofs while payroll was declared as finish carpentry, it reassesses the gap retroactively. One more cap to remember: premium is only charged on the first $121,700 of earnings per worker in 2026, so a worker paid $200,000 is charged on $121,700, not the full amount.
How does experience rating change your rate?
The class rate is the start, not the finish. Under the WSIB Rate Framework (in force since 2020), your rate moves up or down within risk bands based on your own claim costs over up to the last six years. A clean record pulls you toward a lower band below the class average; costly lost-time claims push you into higher bands for years. If you ran a business before 2020, forget the old program names — NEER, CAD-7, MAP and SCIP were all discontinued when the Rate Framework launched. There is now one prospective, experience-adjusted rate per employer per class. The practical takeaway is unchanged: a single serious fall claim on a small contractor's account can raise premiums materially for several years, so safety is a direct line item, not just a legal duty.
Is WSIB coverage mandatory for you?
For most Schedule 1 industries with at least one worker, yes. Construction is the strict case: coverage is mandatory for every construction employer and — since January 1, 2013 — for independent operators, sole proprietors, partners and executive officers on their own labour earnings, regardless of headcount. Professional services (architects, engineers, consultants — Class L at $0.18) and some financial services are not compulsory but can opt in, and many do, because WSIB is no-fault: injured workers get benefits without suing, and employers get protection from those lawsuits. On a jobsite this matters even if you're a one-person sub: general contractors demand a WSIB clearance certificate from every subcontractor, because without it the principal inherits liability for the sub's injuries. Operating without coverage when it's required brings retroactive premium assessment plus penalties under the Workplace Safety and Insurance Act.
Common mistakes that trigger a WSIB audit
- Declaring the cheapest activity. Booking roofing payroll as "finish carpentry" or "office" to catch a lower class is the classic audit flag — WSIB reverses it retroactively with the gap owing.
- Confusing residential and non-residential. G1 (residential, $2.18) and G6 (non-residential, $1.61) are different subclasses. Build both? WSIB looks at your predominant activity — the work over 50% of payroll.
- Assuming a sole proprietor is exempt. In construction you are not; you register and pay premium on your own labour earnings.
- Using a stale rate. WSIB republishes class rates every year. Always confirm the year — the figures on this page are 2026.
How to use this tool
Type your trade, job, or NAICS code into the search bar. The tool matches your activity and shows its WSIB class or subclass, the 2026 class rate per $100 of insurable earnings, mandatory-vs-optional coverage, and the common trade names under each code. Browse by NAICS sector chip if you want to scan a whole sector — for example, all of construction — to make sure you're not sitting in the wrong subclass. The rates shown are 2026 class rates before your employer-specific risk-band adjustment; your final premium depends on your own claims experience and insurable earnings. Use the print button for a PDF to keep or hand to your accountant, then take the class into the WSIB Premium Calculator. For your exact rate, call WSIB at 1-800-387-0750 or sign in at wsib.ca. For the full set of free compliance tools, see the WSIB & OHSA toolkit; if you run crews, ToolFluency's Ontario contractor app ties timesheets, jobs and invoicing together in one place.
About NAICS Code Lookup
NAICS — the North American Industry Classification System — is the taxonomy Statistics Canada and WSIB use to group employers by predominant business activity. Under the WSIB Rate Framework, each Schedule 1 employer's predominant NAICS activity maps to one of roughly 34 classes and subclasses, and the class sets the published premium rate per $100 of insurable earnings.
By the ToolFluency team · Updated September 2026
Free NAICS code lookup for Ontario employers. Search by trade or job to find your WSIB class or subclass, the 2026 premium rate per $100 of insurable earnings, and whether coverage is mandatory — construction (G1–G6), manufacturing, retail, trucking and more.
How to use
- Type your trade or job into the search box (for example 'roofing', 'framing', 'electrician', 'restaurant', 'long-haul trucking'). The tool matches your NAICS activity and shows the WSIB class or subclass it maps to. Be specific: 'residential building' (Class G1) and 'commercial building' (Class G6) are different classes at different rates.
- Filter by NAICS 2-digit sector chip (23 Construction, 31-33 Manufacturing, 44-45 Retail, 48-49 Transportation, 54 Professional, 62 Healthcare, 72 Accommodation/Food) to browse related codes and confirm you are not misclassified into a neighbouring class.
- Read the matched result: the NAICS code, the WSIB class or subclass it maps to, the 2026 published class rate per $100 of insurable earnings, and whether coverage is mandatory. WSIB sets one rate per class, so many NAICS codes share the same rate — roofing, framing and masonry (all NAICS 2381) all sit in subclass G3 at $3.55.
- Note the coverage rule: construction is mandatory for every employer, and for sole proprietors, partners and executive officers on their own labour earnings (in effect since January 1, 2013). Professional services (architects, engineers, consultants — Class L, $0.18) are optional and can elect to opt in.
- Estimate your premium: insurable earnings × class rate ÷ 100. The 2026 maximum insurable earnings ceiling is $121,700 per worker (up from $117,000 in 2025). Earnings above the cap for any one worker are not charged premium.
- Layer on experience rating. Under the WSIB Rate Framework (2020 onward) your class rate moves up or down within risk bands based on your own claim costs over up to six years — the legacy NEER, CAD-7, MAP and SCIP programs were discontinued in 2020. A clean claims record earns a lower risk-band rate; costly claims push you higher.
- Weigh the cost of misclassification. On $400,000 of insurable earnings, roofing (Class G3, $3.55) costs $14,200 a year while finish carpentry (Class G5, $2.15) costs $8,600. Declaring the wrong class is a top WSIB audit trigger and is reversed retroactively — document your predominant activity honestly, then carry the matched class into the WSIB Premium Calculator to finish the estimate.
Examples
Residential roofing contractor
Search 'roofing' → match: NAICS 238160 → WSIB subclass G3 (Foundation, Structure and Building Exterior Construction), 2026 rate $3.55 per $100. Mandatory Schedule 1 coverage. With $400,000 of insurable earnings: premium = 400,000 × 3.55 ÷ 100 = $14,200 before your employer-specific risk-band adjustment.
Engineering office, 4 employees
Search 'engineering' → match: NAICS 541330 → WSIB Class L (Professional, Scientific and Technical), 2026 rate $0.18 per $100. Coverage is optional and can be elected. Opted in with $250,000 of insurable earnings: premium = 250,000 × 0.18 ÷ 100 = $450.
Frequently asked questions
What is a NAICS class and how does it affect WSIB premiums?
NAICS — the North American Industry Classification System — is the taxonomy Statistics Canada and WSIB use to group employers by predominant business activity. Under the WSIB Rate Framework, each Schedule 1 employer's predominant NAICS activity maps to one of roughly 34 classes and subclasses, and the class sets the published premium rate per $100 of insurable earnings. Higher-injury classes (construction subclass G3 — foundation, structure and building exterior — pays $3.55 in 2026) cost far more than lower-risk ones (professional services, Class L, pays $0.18). WSIB sets one rate per class, so many NAICS codes share the same rate.
Does WSIB set a rate for each NAICS code?
No. WSIB does not publish a separate premium rate for every 6-digit NAICS code. It groups activities into classes and subclasses and publishes one rate per class. Construction (Class G) has six subclasses: G1 Residential Building ($2.18), G2 Infrastructure ($1.72), G3 Foundation/Structure/Exterior ($3.55), G4 Building Equipment ($1.54), G5 Specialty Trades ($2.15) and G6 Non-residential Building ($1.61) for 2026. Your own claims experience then moves your rate up or down within risk bands under the Rate Framework.
What are the 2026 WSIB construction premium rates?
For 2026 the six construction subclass rates per $100 of insurable earnings are: G1 Residential Building Construction $2.18, G2 Infrastructure Construction $1.72, G3 Foundation, Structure and Building Exterior $3.55, G4 Building Equipment Construction $1.54, G5 Specialty Trades Construction $2.15, and G6 Non-residential Building Construction $1.61. Roofing, framing and masonry fall in G3; electrical and plumbing in G4; drywall, painting, flooring and finish carpentry in G5. The all-Ontario average rate for 2026 is $1.23.
Is WSIB coverage mandatory for every Ontario employer?
It is mandatory for most Schedule 1 industries with at least one worker. Construction is mandatory for every employer and, since January 1, 2013, for independent operators, sole proprietors, partners and executive officers on their own labour earnings. Some sectors — banks, insurance, financial services and professional services in some forms — are not compulsory but can opt in. Many general contractors require a WSIB clearance certificate from every subcontractor regardless of whether the sub's coverage is technically optional; without it the principal inherits the liability. Working without coverage when required carries financial penalties and retroactive premium assessment under the Workplace Safety and Insurance Act.
What's the difference between Schedule 1 and Schedule 2?
Schedule 1 employers — most Ontario private-sector industries — pay annual premiums into the WSIB collective insurance pool, and the WSIB pays claims out of that pool. Schedule 2 employers (much of the public sector and some federally regulated industries like railways and airlines) self-insure: they reimburse WSIB the full cost of every claim their workers file, plus an administration fee, rather than paying a class premium rate. Most small businesses are Schedule 1 unless explicitly excluded.
What is the maximum insurable earnings for WSIB premiums?
The annual maximum insurable earnings per worker is $121,700 for 2026, up from $117,000 in 2025 and $112,500 in 2024. Premium = insurable earnings × class rate ÷ 100, calculated per NAICS activity. Earnings above the cap for any single worker are not charged premium. For example, a worker paid $200,000 in construction subclass G3 ($3.55) is charged premium on $121,700, not $200,000 — capped premium = 121,700 × 3.55 ÷ 100 = $4,320.35.
What if my business does multiple activities, and how do I appeal my class?
WSIB classifies on your predominant activity — the work occupying more than 50% of payroll. A general contractor who also does some roofing sits in its building-construction class, not roofing's higher subclass. If a secondary operation carries materially different risk and a separately managed workforce, WSIB may assign more than one class. Misclassification (declaring office payroll while workers are on roofs) is a top WSIB audit trigger and is reversed retroactively. To dispute your class, request a reassessment through WSIB Employer Account Services with your activity description, payroll allocation and supporting documents; if the decision is unfavourable you can appeal to the WSIB Appeals Services Division and then the Workplace Safety and Insurance Appeals Tribunal (WSIAT).
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