NAICS codes for Canadian contractors: the complete construction list

Where NAICS does drive matching: US federal contracting. If you pursue work through SAM.gov in the United States, NAICS codes are central. Buyers set a NAICS code per solicitation and small-business size standards are defined by NAICS. So a Canadian contractor bidding cross-border needs an accurate NAICS code for the US system, even though it is secondary at home.

Where your NAICS code actually gets used

NAICS still earns its keep in Canada, just not where contractors expect. The real uses:

• Canada Revenue Agency tax filing. The CRA uses NAICS as its "industry code" on business returns. The T2125 form and corporate returns ask for the six-digit code that matches your main activity.
• Statistics Canada. Business surveys and the Business Register classify you by NAICS. This is the system's original purpose.
• Provincial and prequalification forms. Some provincial procurement systems, vendor-of-record applications, and general-contractor prequalification packages ask for your NAICS code as a quick industry descriptor.
• WorkSafe and WCB classification context. Workers' compensation boards run their own classification units, but they map closely to NAICS-style industry activity, and your stated industry should be consistent across all of them.
• US federal contracting (SAM.gov). As above, central to the US system.
• Banking, insurance, and grant applications. Lenders, insurers, and grant programs often ask for an industry code to assess and categorize your business.

The thread running through all of these: consistency. Your NAICS code should describe the same primary activity everywhere it appears. A firm that calls itself 238140 (masonry) on its tax return and 236220 (commercial building) on a prequalification form invites questions it does not need.

How to find your NAICS code

Finding the right code takes about fifteen minutes. The order matters, because the wrong starting point sends you to a plausible-but-wrong code.

Step 1: Identify your primary activity. NAICS classifies you by the single activity that generates the most revenue, not by everything you are capable of. A firm that does 70 percent masonry and 30 percent concrete foundations is a masonry contractor for NAICS purposes. Decide what you mainly get paid for before you search.

Step 2: Search the Statistics Canada NAICS tool. Use the official Statistics Canada NAICS 2022 search. Type a keyword that matches your work (such as "roofing," "highway," or "electrical"), or browse the hierarchy starting at sector 23.

Step 3: Drill down to six digits. Move from the two-digit sector (23) to the three-digit subsector (236, 237, or 238), then the four-digit group, then the six-digit Canadian industry. Read the official definition for your candidate code. Statistics Canada lists examples of what is and is not included, which settles most edge cases.

Step 4: Cross-check the CRA industry code list. The Canada Revenue Agency publishes the same NAICS codes as industry codes for tax filing. Confirm your code appears there so your tax return and other registrations stay aligned.

Step 5: Record it, and note where procurement codes differ. Save your six-digit code for tax, statistics, and prequalification. Then, separately, identify the GSIN or UNSPSC commodity codes you will need on CanadaBuys. They are different systems for different jobs.

How to pick the right code (and handle multiple trades)

Two rules cover almost every case.

The primary-activity rule. When one code is required, use the one that matches your largest revenue line. Not your most prestigious work, not your newest service line. Whatever pays the most bills.

The secondary-code rule. Many systems let you record more than one NAICS code. A firm that genuinely splits work across trades can list a primary plus secondaries. A contractor doing both poured foundations and masonry might run 238110 primary and 238140 secondary. Use secondaries where the form allows it, but never invent a primary code that overstates what you mostly do.

If you are stuck between two codes, read both Statistics Canada definitions side by side and pick the one whose "includes" examples best match your actual jobs. When the line is genuinely blurry (say, a design-build firm that both designs and constructs), classify by where the majority of the contract value sits, and ask your accountant if it affects tax treatment.

Common mistakes

Assuming NAICS controls CanadaBuys matching. The big one. It does not. Federal commodity matching runs on GSIN, moving to UNSPSC. Set those up separately or you will miss opportunities while wondering why your "perfect" NAICS code produced silence.

Picking a three-digit or two-digit code when six is required. "23" and "238" are categories, not your code. Almost every form wants the full six-digit number. Giving a partial code reads as carelessness on a prequalification.

Choosing the most impressive code instead of the accurate one. A specialty trade firm that lists itself as a general building contractor (236) to look bigger creates a mismatch with its actual project history and tax filings. Classify what you do, not what you wish you did.

Using a US-granular code in Canada. The US splits some construction industries into more six-digit codes than Canada does (residential construction is one example). Use the NAICS Canada list above for Canadian forms, and the US list for SAM.gov. They share structure but are not identical at the most detailed level.

Your NAICS code is plumbing, not strategy. Get it right once, keep it consistent everywhere, and move on to the work that actually wins contracts. If construction tenders are your target, the real levers are bonding, certifications, and compliant bids, which we lay out in how to bid on government construction contracts in Canada. And before you commit hours to any specific tender, run it through the bid/no-bid framework and check it against the mandatory criteria.