Advertising Rules for Engineering Firms in Ontario
Engineering firms can advertise, but Ontario's rules shape what they can say and how they describe their projects. This page summarizes the main points for marketing.
Can engineering firms advertise in Ontario?
Engineering firms can advertise in Ontario, provided they hold a Certificate of Authorization and follow the advertising limits in Ontario Regulation 941. PEO states that anyone offering professional engineering services to the public must hold a Certificate of Authorization, and holders must carry professional liability insurance, with some exceptions.
This page summarizes points that affect marketing. It is not legal advice. Check PEO's current guidance, and other provinces' regulators if you work outside Ontario.
| Topic | What it means for marketing |
|---|---|
| Certificate of Authorization | Required to offer engineering services to the public |
| "Engineers" in ads | Only C of A holders may advertise as engineers |
| "Consulting engineers" | Restricted title; needs PEO designation and permission for firm names |
| Factual claims | Ads must be factual, professional and dignified, without exaggeration |
| Other engineers | No direct or indirect criticism of other engineers or firms |
| Seals | Do not use a member's seal or PEO's seal in advertising |
| Project credit | Do not claim more responsibility than you had; acknowledge associated firms |
What does PEO say about engineering advertising?
PEO's Advertising Information for Certificate of Authorization Holders explains that section 75 of Regulation 941 prohibits criticizing other members or firms and using seals in advertising. It describes ads as appropriate when they are factual, professional and dignified, and flags exaggerated project performance and overstated responsibility as inappropriate.
Who can use the title "consulting engineer"?
Only PEO members designated by PEO can use "consulting engineer", and firms need PEO's permission to use "consulting engineers" in their corporate names. PEO's guidance on offering services to the public notes that holding a Certificate of Authorization does not by itself allow a firm to advertise as consulting engineers. Check your firm name, website, signage, directories and ads.
How should engineering firms describe projects?
Engineering firms should describe their actual role on each project, name the disciplines and scope they delivered, and acknowledge the architect, prime consultant and other firms involved. Photos of a whole building can imply more involvement than you had, so caption them with your scope. Performance claims must be accurate.
| Risky | Accurate |
|---|---|
| "We designed the new Riverside Library." | "Structural engineering for the new Riverside Library. Architect: Example Architects. Prime consultant: Example Architects." |
| "Our design cut energy use by 60%." (without data) | "Mechanical design targeting a 40% reduction in modelled energy use compared with the reference building, per the energy model." |
How to write a full project sheet with this credit built in is on project portfolio.
Credit your role, credit your partners.
Accurate credit protects your reputation and your relationships.
What do these rules mean for ads, websites and LinkedIn?
These rules mean engineering marketing should be specific and factual: name sectors, services and real projects with accurate roles, show qualifications and licences, and avoid superlatives, guarantees and comparisons that criticize others. The same applies to search ads, LinkedIn posts, proposals and directory listings.
Ad wording is on Google Ads examples, the website on website design, posts on LinkedIn, messaging on sector positioning and partner credit on architects and contractors.
Do other rules apply to engineering marketing?
General rules also apply: Canada's anti-spam law for commercial email, privacy law for client information, and the Competition Act's rules on misleading claims. Client contracts may restrict naming the client or showing project details. Check confidentiality terms before publishing any project.
Frequently asked questions
Can engineering firms advertise in Ontario?
Yes, with a Certificate of Authorization and within Regulation 941's limits.
Who needs a Certificate of Authorization?
Anyone offering professional engineering services to the public in Ontario.
Can we call ourselves consulting engineers?
Only with PEO designation, and firms need permission to use it in their names.
Can we compare ourselves with other firms?
Avoid criticizing other engineers or firms, directly or indirectly.
Can we show our seal in marketing?
No. Seals should not be used in advertising.
How should we credit shared projects?
State your role and acknowledge associated firms.
Do these rules apply to LinkedIn?
Yes. Treat posts and profiles as advertising.
Sources & further reading
Platform rules and local programs change. These sources let you check the facts on this page, last checked October 21, 2026.