The Certificate of Practice is not an incorporation question
Under the Architects Act, no one offers architectural services to the public in Ontario without a Certificate of Practice from the OAA, and that holds for a sole proprietorship, a partnership and a corporation alike. Incorporating does not earn the certificate, and staying unincorporated does not excuse you from it. The real question is narrower than most new principals expect: since the OAA governs the practice either way, is a corporation the right wrapper for yours?
What changes when the certificate holder is a corporation is that the Act starts examining the corporation's anatomy: who holds the shares, who sits on the board, whose supervision the work runs under. Get those wrong in the articles and the application stalls; get them right and the certificate attaches to the Ontario corporation, with the practice name cleared through the OAA on the way. Mandatory professional liability coverage through Pro-Demnity applies in every form of practice, so insurance is a cost of practising, not a cost of incorporating.
Who must hold what
The conditions for a corporate certificate holder are precise enough to draft from, and they shape the articles before any tax thinking begins:
| Element | What the Architects Act requires |
|---|---|
| Voting shares | At least 51% of the votes, legally and beneficially owned by OAA members |
| Board of directors | A majority of the directors are members |
| Supervision | Architectural services run under the personal supervision and direction of a member |
| Remaining equity | The minority of votes, and non-voting classes, are where non-members may sit, within the Act's limits |
| Combined practices | The Act makes room for joint architecture-and-engineering firms, with licensed engineers inside the ownership math |
Legally and beneficially is the phrase that carries the weight: the control block cannot be parked in a trust or held through another company on a member's behalf. The members own it outright, on paper and in fact. And the tests are ongoing rather than one-time, so a retirement, a death or a share sale can put the certificate offside. A shareholder agreement that says exactly what happens to a member's block on exit is not boilerplate here; it is what keeps the practice licensed through a transition.
Family and holdcos live in the minority room
A holding company is not an OAA member, so it can never hold the control block; the same goes for a non-architect spouse. What either can hold is minority equity, and whether that is worth building depends on what the practice retains. Surplus moved to a holdco by intercorporate dividend sits beyond the reach of the operating company's commercial creditors, and a leaner operating company is simpler to hand to a successor when that day comes. The design has to clear the OAA first and the tax rules second: TOSI taxes most dividends to family members at the top rate unless an exclusion applies, a subject our architect tax planning page treats in full.
Our drafting advice runs one way: build the share classes for the structure you will want in year five, not the one you need in month one. An unused non-voting class in the original articles costs nothing; adding it later means articles of amendment and another pass through the regulator.
When the corporation actually pays
The tax case only works if money stays inside. Profit retained in the corporation is taxed at roughly 12.2% on the first $500,000 of active income in Ontario; the same profit on a sole practitioner's personal return faces rates reaching 53.53%. A principal who draws every dollar to live on gets no deferral, just a T2, a minute book and payroll remittances. The principals who benefit are those whose practice out-earns the household, which often arrives around the time a studio commits to its first salaried technologist and starts holding cash between project waves.
What the corporation never does is stand between a member and professional responsibility. The work runs under personal supervision and Pro-Demnity responds to claims; the corporate shield covers the commercial layer instead — the studio lease, workstation and plotter financing, a fee dispute that turns litigious.
Timing is more forgiving than principals fear. An established sole practice can move into a corporation on a tax-deferred basis under a section 85 rollover, goodwill, work in progress and equipment included, so waiting is rarely costly, and incorporating before there is profit to retain is merely early, not wrong.
The setup, run once
Our Incorporation service runs the whole sequence from our Mississauga office as one engagement: the name checked against corporate records and OAA requirements; articles drafted with the 51% control block, a members-majority board and a spare non-voting class built in; the Certificate of Practice application prepared to match; then CRA program accounts — corporate tax, HST from the first invoice since design fees carry 13% HST, payroll when the first salary runs — and banking and books that start clean. From there the structure hands off to Tax Planning & Advisory, where the owner-pay and holdco decisions the structure was built for actually get made. The fee comes in writing after a free 15-minute discovery call.
