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Common Post-Closing Disputes in Ontario Business Sales

The issues that most often cause disputes between buyer and seller after an Ontario business sale closes, and how well-drafted agreements resolve them.

Buying & Selling a Business6 min readTSLBy the Treadstone Law team · OntarioUpdated 2026-07
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Key takeaways
  • Breach of Representations and Warranties The seller made a series of statements in the purchase agreement — about financial statements, contracts, employees, compliance, and more.
  • Well-drafted purchase agreements anticipate this and build in a resolution mechanism — an accountant referral for financial disagreements, arbitration for broader disputes — rather than…
  • - Go back to the agreement first, not your memory of the negotiation.

Closing day feels like the finish line, but for many Ontario business deals it's really the start of a new phase — one where the purchase agreement's fine print finally gets tested against reality. Most closings never turn into a fight. But when post-closing disputes do happen, they tend to cluster around a fairly predictable set of issues.

Knowing what those issues usually are — and how a well-drafted agreement handles them — helps both buyers and sellers negotiate smarter before closing, and react faster if a problem does surface afterward.

The Usual Suspects

1. Breach of Representations and Warranties

The seller made a series of statements in the purchase agreement — about financial statements, contracts, employees, compliance, and more. If one of those turns out to be false, and the buyer suffers a loss as a result, that's a classic indemnity claim. This is one of the single most common sources of post-closing friction, precisely because reps and warranties cover so much ground.

2. Working Capital and Purchase Price Adjustments

Most purchase agreements price the deal off an estimated closing statement, then true it up against a final statement prepared after closing. When the buyer's and seller's accountants land on different numbers — often because of how inventory, receivables, or accruals were counted — a dispute over the adjustment amount can follow.

3. Earn-Out Calculations

Where part of the price is contingent on the business hitting future performance targets, disagreements often arise over how those targets are measured, whether the buyer ran the business in a way that affected the numbers, or how specific line items should be treated.

4. Undisclosed Liabilities

A debt, lawsuit, or compliance issue the buyer didn't know about at closing surfaces afterward. Whether it's the seller's problem or the buyer's depends heavily on deal structure (asset vs. share sale) and on what the disclosure schedule actually said.

5. Restrictive Covenant Breaches

Where a seller agreed to a non-compete or non-solicitation obligation as part of the deal, disputes can arise if the buyer believes the seller has started competing, poaching staff or customers, or otherwise crossed a line the agreement was meant to prevent.

How These Disputes Are Typically Resolved

Dispute TypeCommon Resolution Path
Breach of reps/warrantiesFormal indemnity claim under the agreement, subject to any survival period, basket, and cap
Working capital / price adjustmentOften referred to an independent accountant for a binding determination, per the agreement's dispute mechanism
Earn-out calculationDepends heavily on how the earn-out clause was drafted; may go to an accountant, an expert, or arbitration
Undisclosed liabilitiesIndemnity claim if covered by the reps/warranties; otherwise depends on whether the liability was assumed
Restrictive covenant breachOften starts with a demand letter; can escalate to an injunction application or damages claim

Well-drafted purchase agreements anticipate this and build in a resolution mechanism — an accountant referral for financial disagreements, arbitration for broader disputes — rather than leaving every disagreement to default straight into a lawsuit.

What to Do the Moment a Dispute Surfaces

Reducing the Odds of a Dispute Reaching This Stage

Frequently asked questions

Do most post-closing disputes end up in court?

No. Many are resolved through the mechanism the agreement itself sets out — direct negotiation, an accountant referral, or arbitration — because most well-drafted agreements are built to avoid a full lawsuit for routine disagreements. Litigation tends to happen when the dispute is large, the relationship has broken down, or the agreement's dispute mechanism doesn't clearly cover the issue.

Can a buyer walk away from the deal after closing if they find a serious problem?

Generally no, not in the sense of unwinding the transaction. Once a deal has closed, the buyer's usual remedy is a claim under the purchase agreement — typically an indemnity claim — rather than rescission. Whether other remedies are available depends heavily on the specific facts and the wording of the agreement.

How long after closing can these disputes still come up?

It varies by the type of claim and what the agreement says. Indemnity claims for breach of representations and warranties are usually subject to a survival period set out in the agreement itself; other issues, like an earn-out dispute, follow their own timeline tied to when the relevant milestone is measured.

Is it worth trying to resolve a dispute without a lawyer first?

Direct conversation between the parties (or their accountants, for a numbers dispute) often resolves smaller issues faster and more cheaply than immediately escalating. But once a real disagreement over money or interpretation of the agreement emerges, involving a lawyer early tends to protect your position better than waiting.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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