- In a full buyout, the buyer becomes the sole owner and the seller walks away.
- Percentage of ownership isn't just a number — it determines what you can and can't do afterward.
- Before you agree to buy in, find out whether a shareholders' agreement already exists, and read it closely.
Not every business purchase is an all-or-nothing transaction. Sometimes a buyer wants in as a minority investor. Sometimes an owner wants to bring in a working partner without giving up control. Sometimes a majority stake changes hands while a founder stays on with a smaller piece of the company. All of these are versions of a partial share purchase — buying some, but not all, of a corporation's outstanding shares.
A partial purchase looks similar to a full buyout on paper, but the legal analysis is different in almost every direction. You're not just negotiating a price with a seller who's leaving. You're negotiating your ongoing relationship with people who are staying.
This article walks through what changes when you're buying part of a business rather than the whole thing, and what to settle before you sign anything.
What Changes When You're Not Buying It All
In a full buyout, the buyer becomes the sole owner and the seller walks away. In a partial purchase, the existing shareholders (or some of them) remain in place alongside you. That means the corporation's constating documents, any existing shareholders' agreement, and the practical relationships among the owners all survive the transaction — and you're stepping into the middle of them.
Before you negotiate price, you need to understand exactly what you're buying into: who else owns shares, what agreements already govern how they can be transferred, and what rights (or restrictions) attach to the specific shares you're acquiring.
How Much of the Company Are You Actually Buying?
Percentage of ownership isn't just a number — it determines what you can and can't do afterward.
| Stake | Practical effect |
|---|---|
| A small minority stake | Limited influence over day-to-day decisions unless specific protections are negotiated (board seat, veto rights, information rights) |
| A stake approaching or at half | May create a genuine two-way partnership dynamic, with real deadlock risk if there's no tie-breaking mechanism |
| A stake giving working control | Generally lets you direct ordinary business decisions, though the company's articles or a shareholders' agreement may still reserve certain major decisions to a supermajority vote |
| A large majority, short of all the shares | Broad control, but remaining minority shareholders may still hold statutory or contractually negotiated protections that limit what you can do to or with their interest |
A useful fact to anchor this: under Ontario's Business Corporations Act and its federal counterpart, a corporation's own sale of substantially all of its property outside the ordinary course of business generally requires shareholder approval by special resolution — but a purchase of shares directly from a shareholder is a transaction between shareholders, not a transaction by the corporation, and doesn't itself trigger that corporate-level approval requirement. The corporate-approval question and the shareholder-transfer question are separate.
Why the Existing Shareholders' Agreement Matters More Than the Purchase Price
Before you agree to buy in, find out whether a shareholders' agreement already exists, and read it closely. These agreements commonly include:
- Rights of first refusal — requiring a selling shareholder to offer their shares to existing shareholders before selling to an outsider like you.
- Consent-to-transfer provisions — requiring the board or other shareholders to approve a new shareholder joining.
- Pre-emptive rights — giving existing shareholders the right to maintain their percentage if new shares are issued.
- Drag-along and tag-along rights — which can force a minority shareholder to join a future sale, or let them ride along on the same terms.
If no shareholders' agreement exists yet, that's not a reason to skip one — it's a reason to negotiate one as a condition of your purchase, before you become a co-owner without any ground rules in place.
Pricing a Partial Stake
Valuing part of a business isn't the same as pro-rating the value of the whole thing. A stake with no control attached is often priced at a discount to reflect the buyer's limited say over decisions, distributions, and an eventual exit. A stake that hands over working control can command the opposite treatment. Exactly how much of an adjustment applies in either direction is deal-specific and not something a general article can quantify — it's a question for negotiation, supported by a qualified business valuator where the numbers are meaningful.
Due Diligence for a Partial Purchase
Your due diligence list overlaps heavily with a full buyout, but a few items matter more when you're becoming a co-owner rather than a sole owner:
- The existing shareholders' agreement and corporate minute book
- Related-party transactions between the company and its current owners
- Historical dividend or distribution policy
- Any existing shareholder disputes or unresolved governance issues
- How major decisions have actually been made in practice, not just on paper
Frequently asked questions
Do I need the other shareholders' consent to buy in?
It depends entirely on the company's articles and any shareholders' agreement. Some permit free transfers; many require consent, offer the shares to existing shareholders first, or both. Check before you negotiate price with the selling shareholder.
Can I buy shares directly from the company instead of from an existing shareholder?
Yes — that's a share subscription (the company issues new shares to you) rather than a transfer of existing shares, and it's a different mechanism with its own considerations, including dilution of the current shareholders and pre-emptive rights they may hold. Your lawyer can advise which structure fits your situation.
What happens to my investment if the majority owner later sells the whole company?
That depends on whether a drag-along right exists. If it does, you may be required to sell your shares on the same terms as the majority sale. If it doesn't, you could be left holding a minority stake in a company under new ownership, with no guaranteed exit. This is exactly the kind of provision worth negotiating at the time you buy in, not after a sale is already on the table.
Is a partial share purchase taxed differently than buying or selling 100%?
The general tax treatment of a share sale — capital gains to the selling shareholder — applies regardless of what percentage is sold. An individual seller may potentially shelter part of the gain using the Lifetime Capital Gains Exemption if the shares qualify, but qualification depends on specific tests that need to be reviewed with an accountant for your actual transaction, not assumed from a general rule.
This is a business purchase or sale question
Start a file online — flat, published fees, reviewed by a licensed Ontario lawyer before a dollar is owed.