Do you actually need a
shareholders' agreement?

By Jonathan Kleiman, Barrister & Solicitor · Published June 2026

"Do I really need a shareholders' agreement?" I get asked this constantly — by two friends who just incorporated a startup, by a parent bringing a child into the family company, by a founder about to take on an investor. Usually there is a hopeful note in the question, because the agreement feels like a cost and a hassle, and the relationship feels strong enough to skip it. So let me answer it plainly, the way I would across a desk.

No, a shareholders' agreement is not legally mandatory. Nothing in Ontario law forces you to have one. Your corporation is validly formed and can run for years without it. But — and this is the part people miss — "no agreement" does not mean "no rules." The moment you have more than one shareholder, your relationship is governed by something. If you did not write the rules, then Ontario's Business Corporations Act (the OBCA), plus your articles of incorporation and corporate by-laws, wrote them for you. The real question is therefore not whether you are governed, but whose terms govern: yours, or a one-size-fits-all statute that was never designed around your business.

Below I will explain what a shareholders' agreement actually is, what the OBCA defaults do to you when you skip one, a straightforward decision tree for figuring out whether you need one, a few of the ways I have watched this go wrong, why templates so often fail, and the difference between an ordinary agreement and a unanimous shareholder agreement. None of this is legal advice for your specific situation — but after years of both drafting these agreements and untangling the disputes that arise without them, this is what I want every co-owner to understand before they decide.

What a shareholders' agreement actually is

A shareholders' agreement is a private contract among the shareholders of a corporation. It governs the things the incorporation paperwork does not: how the business is run day to day, how big decisions get made, how and when shares can change hands, what an owner is entitled to on the way out, and what happens when the owners stop agreeing. Think of it as the rulebook for the relationship between the people who own the company, sitting on top of the corporation itself.

It is worth being clear about what it is not. It is not your articles of incorporation, which create the corporation and set up its share structure. It is not your by-laws, which handle the mechanical housekeeping — how directors are elected, how meetings are called, who can sign. And it is not the OBCA, the statute that supplies a complete set of background rules for every Ontario corporation. The agreement is a separate, optional layer that the owners add on purpose, to replace the parts of that background framework they do not want with terms they do.

Isn't the corporation itself enough protection?

This is the most common misconception, so it is worth meeting head-on. People reason that because they went to the trouble of incorporating — a real legal entity, a separate "person" that owns the business and shields them personally — the structure is complete. Incorporation does important work: it generally separates the company's debts from your personal assets. But that limited-liability shield is about the relationship between the company and the outside world. It says nothing about the relationship between you and your co-owners — and that internal relationship is precisely where co-owned businesses break. A corporation tells the world who owns the company. A shareholders' agreement tells the owners how they will live together. You need both, and the second one is the one almost everyone forgets until it is too late. It is one of the first things I tell people to sort out after they incorporate.

The honest answer: it is about whose rules apply

Here is the reframe I give every founder. Asking "do I need a shareholders' agreement" is a little like asking "do I need a will." Technically no — if you die without one, the law has a default scheme that will distribute your estate. The catch is that the default scheme may bear no resemblance to what you actually wanted. A shareholders' agreement works the same way. Skip it, and the OBCA's defaults quietly become your agreement. They are not malicious; they are just generic, and generic rules rarely fit a specific set of owners with specific contributions, expectations, and exits in mind.

So the useful version of the question is not "am I required to have one." It is "do I want the OBCA to decide what happens when an owner wants out, dies, gets divorced, stops pulling their weight, or simply disagrees — or do I want to decide that myself, in advance, while everyone is still reasonable?" Put that way, the answer becomes obvious for almost every business with more than one owner. The next section is where it stops being abstract: this is what the defaults actually do.

What happens if you don't have one — the OBCA defaults that bite

When there is no shareholders' agreement, the OBCA, your articles, and your by-laws fill every gap. Read these carefully, because they are the rules you are actually living under right now if your corporation is co-owned and unpapered.

• The majority controls — and the minority can be shut out. Shareholders elect the directors, and the directors run the company. A shareholder or group holding more than half the votes controls the board and therefore day-to-day management. A minority owner who is not a director can be excluded from decisions entirely, with no statutory right to a board seat, a job, or a say.
• Ordinary decisions need a majority; fundamental ones need two-thirds. Routine matters pass by an ordinary resolution — a simple majority of the votes cast. The big structural changes (amending the articles, amalgamating, selling substantially all the assets, dissolving the company) require a special resolution, which under the OBCA means at least two-thirds of the votes cast. That cuts both ways: a holder of more than one-third of the votes can block any fundamental change, and two equal owners can block each other on everything.
• There is no buy-out mechanism — and no way out. This is the big one. Nothing in the OBCA gives a shareholder the right to be bought out, sets a price for their shares, or obliges anyone to purchase them. An owner who wants to leave a private corporation has no ready market for their shares and no exit the others must honour. They can be stuck, and so can everyone else.
• On death, shares pass to the estate. Without an agreement, a deceased owner's shares flow to their will and beneficiaries. You can end up co-owning your company with a late partner's spouse or children, with no obligation on anyone to buy them out and no funding to do so.
• Deadlock has no built-in fix. If two equal owners — or two equal factions — genuinely disagree on something that needs a vote, the company simply stalls. The OBCA supplies no tie-breaker. The realistic escapes are negotiation, mediation, or court.
• The minority's real protection is the oppression remedy — which means court. The OBCA's main safeguard for a squeezed-out minority is the oppression remedy (section 248), under which a court can intervene when a company is run in a way that is oppressive, unfairly prejudicial, or unfairly disregards an owner's interests. It is genuinely powerful — a court can even order a buy-out or, as a last resort, wind up the company (section 207). But it is a Superior Court proceeding: slow, expensive, and uncertain. It is a fire extinguisher, not a smoke detector. I cover it in depth in shareholder disputes and the oppression remedy, and it is the kind of fight a shareholder dispute lawyer spends a great deal of time on — almost all of it avoidable with a few clauses agreed up front.

Look at that list and the theme is unmistakable. The defaults handle the corporation's machinery competently, but they are close to silent on the human questions that actually sink co-owned businesses: getting out, being bought out, dying, divorcing, deadlocking, and being frozen out. A shareholders' agreement exists to answer those questions on your terms instead of leaving them to a court and a statute.

The decision tree: when you probably DO need one

Enough theory — here is the practical test I use. A shareholders' agreement is rarely wrong to have, but for some businesses it moves from "good idea" to "do not operate without it." Run through these. If you answer yes to even one, you should have a shareholders' agreement in place.

• Do you have more than one shareholder? If yes, you are already exposed to every default above. This alone is usually enough.
• Is it a 50/50 (or otherwise evenly split) ownership? Equal splits have the highest deadlock risk and the least statutory help. This is the single strongest case for an agreement.
• Are you bringing in an investor? An investor wants protections — information rights, exit rights, anti-dilution; you want to protect your control. None of that exists by default.
• Is a shareholder also a key employee earning equity over time? Without vesting and a leaver buy-out, a co-founder who quits in year one can walk away keeping their full stake.
• Are family members co-owners? Family dynamics and corporate governance need to be kept separate, in writing, before they collide.
• Have owners contributed unequally — money versus sweat, or very different amounts? The defaults will not reflect who put in what; only an agreement can.
• Would you object to a co-owner selling their shares to a stranger, or their spouse or estate inheriting them? If yes, you need transfer restrictions and a buy-out the defaults do not provide.
• Do you care what happens to the business if an owner dies, becomes disabled, divorces, or goes bankrupt? Each of those events has a messy default outcome an agreement can tame.
• Are you planning to sell or exit the business one day? Drag-along and tag-along rights, and an agreed valuation, are the backbone of a clean business exit plan.

The realistic conclusion for most readers: if your corporation has more than one owner, you need a shareholders' agreement, and the more "yes" answers you collected, the more urgent it is. The honest exception is the genuine sole shareholder with no plans to bring anyone in — there is no one to contract with, so there is nothing to sign yet. Even then, the day you add a co-founder, investor, or family member is the day the analysis flips, and the smart move is to have the agreement ready before the new shares are issued. Once you have decided you need one, the companion question is what goes in it — our complete shareholders' agreement checklist walks through every provision clause by clause.

A few ways this goes wrong without one

Abstract risk rarely persuades anyone. So here are three patterns I see again and again — details changed, but the shapes are real — that show what the defaults look like in practice.

The 50/50 deadlock

Two equal owners build a healthy business and never sign an agreement, because they are partners and friends. Years in, they split on a fundamental question — whether to sell, whether to take on debt, whether to fire a key manager who happens to be one owner's relative. Neither can outvote the other. The company freezes: no decision, no compromise, and a business that needs decisions made starts to decay while the owners stew. With no agreed tie-breaker and no buy-sell clause, their only real exits are to negotiate from scratch under pressure, or to fight it out in court. A single deadlock provision — a casting vote, mandatory arbitration, or a shotgun buy-sell — would have given them a clean way through. They had none, because the day to draft it was years earlier, when they got along.

The unfair exit

One owner wants out — better opportunity, burnout, a falling-out, it does not matter. They expect to be bought out at a fair number and move on. But there is no agreement, so there is no obligation on the remaining owners to buy, no agreed price, and no method to value the shares. The departing owner cannot force a sale and the remaining owners cannot force them out; meanwhile the shares of a private company have no open market. Everyone is stuck in a relationship nobody wants, and the only lever left is leverage — or litigation. A buy-out trigger and an agreed valuation method would have turned this into a transaction instead of a standoff.

The unexpected co-owner

An owner dies suddenly. Under the defaults, their shares pass through their estate to their family. The surviving owners now find themselves in business with a grieving spouse who has no experience running the company and a very reasonable need for income, or with adult children who want to be paid out but cannot be, because there is no buy-out obligation and no insurance to fund one. What should have been handled cleanly — the family cashed out at fair value, the survivors keeping control — becomes a painful negotiation between people who never chose to be partners. A death-and-disability buy-out funded by life insurance, the kind of provision a proper exit plan builds in, prevents this entirely.

Why templates and DIY agreements fail

Once people accept they need an agreement, the next hopeful question is whether they can just download one. I understand the instinct, and a template is better than nothing — but only just, and it tends to fail in the exact places that matter. The reason is structural: the valuable provisions in a shareholders' agreement are the ones that have to be tailored, and tailoring is the one thing a template cannot do.

Think about what actually has to fit your specific business. The buy-out triggers and price. The valuation method — formula, annual agreed value, or independent valuator. The deadlock-breaker that suits your particular owners. The death-and-disability funding. The precise overrides of the OBCA defaults you want to change and the ones you want to keep. A generic template either leaves these blank, fills them with boilerplate that does not match your deal, or — worst of all — looks complete while quietly missing the provision you most needed. I have reviewed plenty of template agreements that were technically signed and practically useless, because the one clause the owners were now fighting about was the one the template never addressed. This is the same trap I describe for partnership agreements: the cheap document is cheap precisely because it skips the hard, valuable, business-specific thinking.

Shareholders' agreement vs. unanimous shareholder agreement

One distinction is worth understanding before you sit down with a lawyer, because the word "unanimous" trips people up. Most shareholders' agreements are ordinary contracts among the owners. A unanimous shareholder agreement — a "USA" — is a specific instrument under the OBCA (section 108). Signed by all the shareholders, it can do something an ordinary agreement cannot: it can restrict or remove the powers of the directors, in whole or in part, and transfer those powers to the shareholders themselves, with the force of the statute behind it.

That power comes with a matching responsibility, and it is important to flag. To the extent a USA strips the directors of a power and hands it to the shareholders, the shareholders take on the directors' duties and liabilities for that power — and the directors are relieved of them to the same extent. In other words, you cannot grab the steering wheel and disclaim responsibility for the driving. If you want to understand what those director-level duties and liabilities involve, I cover them in director duties and personal liability in Ontario. For most small corporations the choice between a plain agreement and a USA is a drafting decision your lawyer will guide based on how you actually want to run the company — but both serve the same fundamental purpose: replacing the statutory defaults with terms you chose.

When is the right time to put one in place?

The best time is at incorporation, or immediately after, when the owners are aligned, optimistic, and motivated to be fair to one another. Negotiating the terms of a future separation is dramatically easier when no one yet knows who will want to leave, who will underperform, or whose stake will end up worth the most. Everyone bargains fairly when everyone is behind a veil of ignorance about how things will play out. That is the moment to lock the terms in.

The second-best time is now. If your corporation already has co-owners and no agreement, you are not out of options — you can sign one at any point in the company's life, and a great many businesses do, often after a scare that made the gap vivid. The only real obstacle is that everyone has to agree, and agreement gets harder once owners have started to diverge or a specific dispute is brewing. So the rule of thumb is simple: the further you are from a conflict, the cheaper and easier the agreement is to strike. Do it while you are still on the same side of the table. A Toronto business lawyer can move quickly while the relationship is healthy.

If you are weighing an unincorporated structure instead, the same lesson applies one level down: a partnership agreement does for a partnership exactly what a shareholders' agreement does for a corporation — it governs ownership, control, money, and exit. The structure changes; the need for a written deal between co-owners does not.

Key takeaways

• It is not legally required — but you are governed either way. With no agreement, the OBCA, your articles, and your by-laws supply the rules. The question is whether your terms apply or the statute's.
• The defaults are silent where it matters. They handle corporate machinery but barely address exit, buy-out, death, deadlock, and minority protection — the things that actually break co-owned businesses.
• More than one owner usually means you need one. A 50/50 split, an incoming investor, a shareholder-employee, family co-owners, or unequal contributions each push it from advisable to essential.
• The minority's fallback is court. Without an agreement, a squeezed-out owner's main remedy is an oppression claim in Superior Court — powerful, but slow and expensive compared with a clause agreed in advance.
• Timing is leverage. The agreement is cheapest and easiest to strike when everyone is still getting along; it gets harder the moment a dispute looms.

Frequently asked questions

Do I legally need a shareholders' agreement in Ontario?

No. There is no law that forces a corporation to have a shareholders' agreement, and a company with two, ten, or fifty shareholders is perfectly valid without one. But "not legally required" is not the same as "not needed." If your corporation has more than one shareholder, the absence of an agreement does not mean there are no rules — it means the default rules in Ontario's Business Corporations Act govern instead, and those defaults were not written around your deal. In my experience a shareholders' agreement is one of the highest-value documents a co-owned business can put in place, and skipping it is a false economy.

What happens if we don't have a shareholders' agreement?

You are still governed — just by the Business Corporations Act, your articles, and your by-laws rather than by terms you chose. That means the majority controls the board and ordinary decisions; fundamental changes need a two-thirds "special resolution"; there is no built-in way to force or fund a buyout when an owner wants out, dies, or is pushed out; and a deadlock between equal owners has no clean exit short of going to court. A minority owner's main statutory protection is the oppression remedy, which is powerful but means Superior Court litigation. An agreement replaces these one-size-fits-all defaults with rules that fit your business.

Do I need a shareholders' agreement if there are only two of us?

A two-owner corporation is the situation that needs one most, not least. With two equal shareholders there is no third vote to break a tie, so every serious disagreement is a potential deadlock that can freeze the company. Without an agreement, the defaults give you no tie-breaker, no buy-out mechanism, and no off-ramp except an expensive court application. The friendship or trust that makes the agreement feel unnecessary today is exactly what disappears in the dispute it would have governed. Two owners is the classic case for getting one in place early.

Do I need one if I am the only shareholder?

Generally no. A shareholders' agreement is a contract among shareholders, so with a single owner there is no one to agree with. The one nuance worth knowing is that a sole shareholder can still sign a formal declaration that functions like a unanimous shareholder agreement under the Business Corporations Act, which is sometimes used for governance or planning reasons. But for most solo owners the practical answer is to revisit the question the moment you bring in a co-founder, investor, or family member — because that is the day you need the agreement, and ideally you want it signed before the shares are issued, not after.

Can't we just rely on the Business Corporations Act, our articles, and our by-laws?

You can, but understand what they do and do not cover. The Act, the articles, and the by-laws handle the corporation's structure — share classes, director elections, voting thresholds, meeting mechanics. What they almost never address is the human side of co-ownership: how an owner exits and at what price, what happens on death or a falling-out, how to break a deadlock, whether an owner can compete after leaving, and how to stop the majority from diluting or freezing out the minority. Those gaps are exactly what a shareholders' agreement fills. The statute gives you a corporation; the agreement gives you a deal.

What is the difference between a shareholders' agreement and a unanimous shareholder agreement?

An ordinary shareholders' agreement is a private contract among some or all of the shareholders. A unanimous shareholder agreement (a "USA") is a specific creature of the Business Corporations Act — signed by all shareholders, it can restrict or remove the directors' powers and place them in the shareholders' hands, with statutory force. The trade-off is that a shareholder who takes on a director's powers under a USA also takes on that director's duties and liabilities to the same extent. Whether you want a plain agreement or a USA is a drafting decision; both do the core job of replacing the statutory defaults with your own terms.

What happens to a shareholder's shares if they die without an agreement?

They pass according to that shareholder's will or estate — which can leave you in business with a deceased co-owner's spouse, children, or estate trustee, none of whom you chose and some of whom may have no interest in or aptitude for running the company. Without an agreement there is no obligation on anyone to buy those shares, no agreed price, and no funding to pay for them. A shareholders' agreement fixes this with a mandatory buy-out on death, a valuation method set in advance, and life insurance to fund it — so the surviving owners keep control and the family gets fair value in cash instead of a stake in a business they cannot run.

We are 50/50 — what breaks a deadlock without an agreement?

Very little, and that is the danger. With a 50/50 split neither owner can outvote the other, so a genuine disagreement on a decision that needs a shareholder or board vote simply stalls. The Business Corporations Act offers no built-in tie-breaker. Your realistic options become negotiation, mediation if both will agree to it, or a court application — most seriously, an oppression claim or, as a last resort, asking the court to wind up the company. All of those are slow and expensive. A shareholders' agreement is where you build the tie-breaker — a casting vote, a buy-sell (shotgun) clause, or mandatory arbitration — before the deadlock arrives.

Is it too late to put one in place if we have been operating for years?

No. You can sign a shareholders' agreement at any point in the life of the corporation, and many businesses do exactly that — often after a near-miss that made the gap obvious. The only real catch is that everyone has to agree to the terms, and that is harder once owners have started to diverge. The best time to sign was at incorporation; the second-best time is now, while the relationship is still good and no one is negotiating against a specific dispute. If you have co-owners and no agreement, treat it as overdue rather than impossible.

Can I just use a template instead of hiring a lawyer?

A template is better than nothing, but only just, and it tends to fail exactly where it matters most. The provisions that actually protect you — the buy-out trigger and price, the valuation method, the deadlock-breaker, the death and disability funding, the right overrides of the statutory defaults — are the ones a generic template handles poorly or omits, because they have to be tailored to your specific owners, contributions, and risks. A shareholders' agreement is the document that governs your money, your control, and your exit. The cost of having it drafted properly is small next to the cost of litigating its absence, which is the alternative I see far too often.

Final thoughts

"Do I need a shareholders' agreement?" is really a question about who you want making your decisions when things go wrong. Say no, and you have not avoided having a rulebook — you have simply adopted the OBCA's, which splits control by raw vote count, gives a departing or deceased owner no clean exit, offers no tie-breaker for a deadlock, and points a squeezed-out minority toward a courtroom. Those defaults are not a safety net. They are a generic set of rules that were never written with your business, your co-owners, or your exit in mind.

The good news is that almost all of it is in your hands. A tailored agreement — buy-out triggers and pricing, a real valuation method, a deadlock-breaker, death-and-disability funding, the right overrides of the statutory defaults — converts the riskiest parts of co-ownership into terms you chose on purpose. I have never once seen a co-owned business regret having a proper shareholders' agreement. I have seen many regret not having one, usually from across a negotiating table that an afternoon of drafting years earlier would have spared them.

If your corporation has more than one shareholder — or you are about to bring someone in — the smart move is to sort it out while the relationship is good. A shareholders' agreement lawyer in Toronto can draft one that fits your actual deal and overrides the defaults that do not work for you. Call 416-554-1639 or book a free consultation, and we can map out what your company needs before a problem forces the question.