Is your contract
actually binding?

By Jonathan Kleiman, Barrister & Solicitor · Published June 2026

"We have a deal" and "we have a binding contract" are not the same sentence, and the gap between them is where a lot of my business clients get hurt. People shake hands, trade a few emails, or sign something a friend drafted, and they assume they are protected. Sometimes they are. Often, when something goes wrong, it turns out the "deal" was missing one of the ingredients the law actually requires — and there is nothing solid to enforce.

The flip side surprises people even more. A quick "yes, let's do it for $5,000" typed into an email can absolutely be a binding contract, even with no signature, no letterhead, and no lawyer in sight. Whether something binds you has very little to do with how formal it looks and almost everything to do with whether a handful of essential elements are present.

So in this guide I will walk through what Ontario law actually requires for a contract to be legally binding — offer, acceptance, consideration, intention, capacity, certainty, and legality — then cover written versus oral contracts, what has to be in writing, how electronic signatures fit in, the traps that defeat a "deal," and a plain-language checklist you can run against your own situation. None of this is legal advice for your specific contract, but it is the framework I use every day.

The essential elements of a binding contract

When a court in Ontario asks "is this a contract?", it is really running through a checklist. A legally binding contract generally needs all of the following: an offer, acceptance, consideration, an intention to create legal relations, capacity, certainty of terms, and a lawful purpose. Miss one in a meaningful way and you may not have an enforceable agreement at all. Let me take them one at a time.

1. Offer

A contract starts with an offer — a clear proposal by one party to do (or not do) something on specific terms, made with the intention that it will become binding once accepted. "I'll paint your office for $3,000, starting next Monday" is an offer. It has to be distinguished from an invitation to treat — an invitation to negotiate or to make offers, which is not itself an offer. A price list, an ad, or "what would you pay for this?" is usually an invitation, not an offer. The line matters, because acceptance only creates a contract when there is a real offer on the table to accept.

Why does this distinction earn its own paragraph? Because in business it is constantly blurred. A contractor sends a detailed quote; the client treats it as a binding commitment; the contractor treats it as a starting point for negotiation. Both walk away thinking different things. An offer carries a willingness to be bound on those exact terms the instant the other side says yes. If you are still leaving yourself room — "ballpark," "subject to working out the details," "let me check with my partner" — you are probably inviting negotiation, not making an offer. Knowing which one you are doing, and saying so plainly, prevents a surprising number of disputes.

2. Acceptance

Acceptance is the other party agreeing to the offer on its terms. This is the part that trips people up. Acceptance has to match the offer — what lawyers call the "mirror image" idea. If you respond to my $3,000 painting offer with "sure, but make it $2,500 and start Wednesday," you have not accepted; you have made a counter-offer, and the original offer is gone. A counter-offer puts the ball back in the first party's court. A true acceptance, communicated to the offering party, is what locks the deal. Silence is generally not acceptance — you usually cannot bind someone by saying "if I don't hear back, we have a deal."

The "communicated" part matters more than people expect. Accepting in your head, or scribbling "agreed" on a copy you keep in a drawer, does not form a contract — the acceptance has to reach the person who made the offer. There is one familiar wrinkle: under the so-called "postal rule," acceptance sent by post can take effect when it is mailed rather than when it arrives, though modern instant communication like email is generally treated as effective when received. The practical lesson is simpler than the doctrine: if you mean to accept, say so clearly and send it, and do not assume a deal is done until your acceptance has actually landed with the other side on the terms they offered.

3. Consideration

Consideration is the heart of why bargains are enforceable and gifts usually are not. Each side has to give something of value — money, goods, services, or a promise to do or not do something. It is the answer to "what is each party getting?" A bare promise with nothing given in return is generally not an enforceable contract in Ontario. So "I promise to give you my old laptop for free" is a gift, not a contract — if I change my mind, you cannot sue me for the laptop. But "I'll sell you my laptop for $200" has consideration on both sides and is enforceable. The value does not have to be fair or large; courts will not usually weigh whether you got a good deal. It just has to exist.

Consideration is the element that surprises people most, because it can quietly defeat a promise everyone thought was binding. Say a supplier agrees, mid-contract, to do extra work for the same price as a favour, and later refuses — was that promise enforceable? Often not, if the customer gave nothing new in return. Or a business owner promises an employee a bonus for work the employee was already obligated to do; performing an existing duty is generally not fresh consideration. The recurring lesson is the same: if you want a promise to stick, make sure something of value flows back the other way. Even a token amount can be enough to turn a non-binding gesture into an enforceable bargain.

4. Intention to create legal relations

The parties have to intend to create legal relations — to be legally bound, not just morally or socially committed. Ontario law sorts this with two presumptions. In commercial and business dealings, the parties are presumed to intend legal relations. In purely social or family arrangements, they are presumed not to. So a promise between business owners about a supply arrangement is presumed binding, while a promise to take your sister-in-law to dinner is presumed not to be. These presumptions can be rebutted with evidence, but in the business context you usually start from the assumption that the parties meant it.

5. Capacity

Capacity means the parties must be legally able to contract. Most adults and properly authorized businesses have full capacity, so this rarely comes up — but when it does, it matters. Issues arise with minors (contracts with people under the age of majority are often unenforceable against them, with some exceptions) and with people who lack the mental capacity to understand the agreement they are entering. In a business setting, the practical capacity question is usually about authority: did the person signing actually have the power to bind the company? More on that trap below.

Capacity also has a quieter dimension I see catch business owners: signing in the wrong capacity. If you sign a contract personally when you meant to sign only for your corporation, you can end up personally bound — the opposite of the protection you incorporated to get. Conversely, if you sign "for" a company you have no authority to commit, the company may not be bound at all. The fix is mundane but important: sign in the correct legal name, state your role (for example, as an officer of the company), and make sure whoever puts pen to paper genuinely has the power to do so.

6. Certainty of terms

A contract has to be certain — the essential terms must be clear enough for a court to know what the parties agreed and to enforce it. If the core of the deal is vague or left open, there may be nothing to enforce. This is where the classic "agreement to agree" fails: a deal that says "price to be determined later" or "terms to be negotiated in good faith" often is not binding, because the essential terms are still missing. You do not need to dot every "i," but the heart of the bargain — who, what, how much, by when — has to be settled, not deferred.

There is a sensible balance here. Courts do not throw out a contract just because it has a gap; they will sometimes fill minor details with what is reasonable, or with an agreed mechanism for sorting a term out (for instance, "price to be set by an independent appraiser"). What they will not do is invent the core of a deal the parties never actually agreed. A clause that says "the parties will agree on price later" leaves nothing for a court to enforce; a clause that says "price to be the fair market value as determined by an agreed appraiser" usually does, because there is a definite method. The difference between an enforceable mechanism and an empty "we'll figure it out" is often the difference between a binding contract and a wasted negotiation.

7. Legality

Finally, the purpose and terms must be lawful. A court will not enforce a contract to do something illegal or against public policy. An agreement to do something the law prohibits is not a contract the courts will help you with — no matter how clearly the parties agreed. This rarely surprises anyone in ordinary commerce, but it is a genuine element: the deal itself has to be legal.

Legality can also reach into otherwise ordinary contracts through specific terms rather than the whole purpose. A restrictive covenant that is unreasonably broad, a penalty clause dressed up to punish rather than to estimate genuine loss, or a term that contracts out of a protection the law will not let you waive — any of these can be struck down even though the rest of the agreement is fine. So legality is not just "are we doing something criminal?" It is also "does any term cross a line the courts will not enforce?" For most businesses the answer is no, but it is worth a second look whenever a contract tries to do something aggressive.

From my experience: where deals fall apart

From my experience, the cases that land on my desk almost never fail because the parties disagreed about the law. They fail because, somewhere along the way, one of these elements quietly went missing and nobody noticed until money was on the line. I think of two recurring stories.

The first is the "we were basically agreed" deal. Two business owners trade enthusiastic emails, shake hands, and start performing — one delivers goods, the other starts paying — all before the essential terms (quantity, schedule, what happens on default) are actually pinned down. When the relationship sours, each side has a genuinely different understanding of what was promised, and there is no certain term to enforce. The work was real; the contract was half-built. A few minutes spent writing the core terms down would have saved a year of grief.

The second is the signature that did not bind who everyone assumed it bound. A salesperson, a junior employee, or a part-owner signs "on behalf of" a company they were not authorized to commit. The other side relied on it; the company later says it was never bound. Now there is a fight about authority on top of the underlying dispute. The lesson I draw, over and over, is that the unglamorous habits — get it in writing, settle the essential terms, confirm who can sign — are what actually keep a deal enforceable.

Written vs. oral contracts — and what must be in writing

One of the most common misconceptions I hear is "it wasn't in writing, so it doesn't count." That is usually wrong. Most contracts do not have to be in writing in Ontario. An oral, handshake, or verbal agreement can be fully binding if it has all the essential elements above. The law does not require a signed document for a deal to be real.

There are important exceptions. Under the Statute of Frauds, certain contracts must be in writing to be enforceable — most notably guarantees (a promise to answer for another person's debt or default) and contracts dealing with land or an interest in land (and certain others). If your agreement falls into one of those categories and is not in writing, a court may refuse to enforce it even though everyone agrees there was a deal. So before you rely on a verbal promise to guarantee someone's debt or to sell you property, understand that the writing requirement is doing real work.

Even where an oral contract is perfectly valid, there is a practical problem that I cannot stress enough: proof. A verbal deal can bind you, but if the other side disputes the terms, you have to convince a court what was actually agreed — and "he said, she said" is a hard, expensive way to win. This is precisely why a verbal contract can be enforceable in Ontario and still leave you in a weak position. Put it in writing. Even a short confirming email beats a memory.

Why "get it in writing" is still my standing advice

Given that oral contracts can bind, why do I push every client to write things down? Because a written contract does three things a verbal one cannot. It proves the deal existed; it fixes the terms so they cannot drift in anyone's memory; and it forces the parties to confront the awkward details — price, timing, what happens if things go wrong — that a handshake glosses over. A clear written agreement is not about distrust. It is about making sure everyone is genuinely agreeing to the same thing. For small businesses, a solid service agreement is often the single most useful document to get right.

Does a contract have to be signed to be binding?

Not necessarily. A signature is strong evidence that someone agreed, but it is not a magic requirement for most contracts. An unsigned written agreement, or even an exchange of emails, can bind the parties if the essential elements are there and you can show they intended to be bound. The exception, again, is the categories that the Statute of Frauds requires to be in writing and signed — there, the signature does real legal work. For everyday commercial deals, though, "they never signed it" is not the defence people think it is. What matters is whether the parties actually agreed and meant it.

Electronic contracts and e-signatures

Modern deals happen by email, web form, and e-signature platform, and the law has kept up. Under Ontario's Electronic Commerce Act, electronic contracts and electronic signatures are generally valid. An agreement formed by email, or by clicking "I agree" on a website, can be a binding contract, and an electronic signature can satisfy a requirement that something be signed.

In practice, that means a contract signed through a reputable e-signature service is just as enforceable as ink on paper, and a click-through "I accept these terms" can bind a customer to your terms of service. There are a few exceptions — certain documents, such as wills, are carved out and have their own formalities — but for the overwhelming majority of commercial agreements, electronic acceptance and e-signatures work.

The thing to focus on is evidence: being able to show who signed or clicked, what they agreed to, and when. Good e-signature tools capture exactly that — an audit trail, timestamps, and a fixed copy of the document. A loose email thread can still form a contract, but it is messier to prove. If a deal matters, use a proper e-signature flow rather than relying on "well, he replied 'sounds good.'"

The traps that stop a "deal" from being a real contract

Over the years I have seen the same handful of problems turn confident "we have a deal" conversations into nothing enforceable. These are the traps worth knowing, because each one quietly knocks out an essential element.

No consideration. One side promises something and gets nothing in return. A generous promise — to forgive a debt, to throw in extra work for free, to give something away — can be unenforceable precisely because the other side gave no value back. If you want a promise to be binding, make sure each side is giving something.

Essential terms missing or too vague. The parties agreed on the broad idea but left the core open — the price, the scope, the timeline. Without certainty, there may be no contract. "We'll figure out the details later" is a warning sign, not a deal.

An "agreement to agree" or non-binding letter of intent. This deserves its own flag. A letter of intent or term sheet is frequently meant to be a non-binding placeholder while the real contract is negotiated — and even when it is not meant that way, leaving essential terms "to be agreed" often means it does not bind. People sign these and think the deal is done; it usually is not.

No intention to be legally bound. Especially in social or family contexts, or in early "let's explore this" talks, the parties may never have intended a legal commitment. A casual promise among friends, or an enthusiastic but preliminary chat, may simply not be a contract.

Signing without authority. A person signs "on behalf of" a company they were not actually authorized to bind. This is a big one in business deals. If the individual lacked the authority to commit the company, you may find the company is not bound — and you are left chasing the wrong party. Confirm that whoever signs can actually bind the business.

An illegal purpose. The agreement is to do something unlawful or contrary to public policy. The courts will not enforce it. This is rarer in ordinary commerce but real.

When a contract problem lands on my desk, the first thing I do is run through this list. If one of these traps is present, the question shifts from "what does the contract say?" to "is there an enforceable contract at all?" — and that changes everything about how you approach a dispute. If you are already at the point of a fight, my guide on what counts as a breach of contract in Ontario picks up where this one leaves off.

Can one party change a binding contract on their own?

Generally, no. Once a contract is validly formed, neither side can unilaterally rewrite it — a change to a binding agreement is itself a new agreement, and it needs the same ingredients, including (often) fresh consideration. That is why a mid-stream "I'm raising the price" or "I'm not doing that part anymore" usually cannot be imposed on the other side without their agreement. There are exceptions where the contract itself permits changes, or where both parties consent, but the default is reassuring: the deal you agreed to is the deal, and the other side cannot quietly move the goalposts after the fact.

The "is my contract binding?" checklist

Here is the practical checklist I run, in plain language. If you can answer "yes" to all of these about your agreement, you very likely have a binding contract. A "no" or "not sure" on any of them is where I would dig deeper.

• Was there a clear offer? One party proposed specific terms, meaning to be bound if accepted — not just an invitation to negotiate.
• Was it accepted on its terms? The other party agreed to the offer as made — not with changes that turn it into a counter-offer.
• Did each side give something of value? Money, goods, services, or a real promise on both sides — not a one-way gift.
• Did the parties intend to be legally bound? This is presumed in business dealings, but ask whether it was a real commitment or just talk.
• Did everyone have capacity and authority? Adults of sound mind, and — crucially — anyone signing for a company actually had the power to bind it.
• Are the essential terms certain? The who, what, how much, and by when are settled, not left as "to be agreed later."
• Is the purpose lawful? The deal is not to do something illegal or against public policy.
• If it must be in writing, is it? Guarantees and land deals (among others) have to be in writing under the Statute of Frauds.

Run your own situation through that list. Most legitimate business deals pass easily. The ones that fail tend to fail on the same few points — certainty, consideration, authority, or an "agreement to agree" dressed up as a done deal.

Common mistakes I see

A few patterns come up again and again, and almost all of them are avoidable with a little care up front.

Treating a quote or proposal as a binding contract. A quote is often an invitation to negotiate, not a locked-in deal. People act on a proposal as if it were signed and are surprised when the other side walks. Get the acceptance — clear and on the terms — before you commit resources.

Relying on a handshake for a deal that needs writing. Verbal contracts can bind, but if your deal involves a guarantee or land, the Statute of Frauds may require writing — and a handshake leaves you unable to enforce it. Know which deals carry that requirement.

Leaving the important terms for "later." The most common self-inflicted wound. Parties agree on the exciting parts and defer the hard ones, then discover months later that the uncertainty means there was never a binding contract. Settle the essential terms now.

Letting the wrong person sign. In business, a contract signed by someone without authority to bind the company can leave you with no enforceable agreement against the company at all. Verify authority — and sign in the correct corporate name and capacity.

Assuming "we signed something" means "we're protected." A signed document with missing or vague essential terms, no real consideration, or an illegal purpose can still be void or unenforceable. The signature is not magic; the elements are what matter.

Key takeaways

• Seven elements make a contract binding. Offer, acceptance, consideration, intention to create legal relations, capacity, certainty of terms, and legality — miss one in a real way and you may not have an enforceable contract.
• Most contracts don't need to be in writing — but some do. Oral contracts can bind, yet under the Statute of Frauds, guarantees and land deals (among others) must be in writing to be enforceable.
• Electronic counts. Under Ontario's Electronic Commerce Act, electronic contracts and e-signatures are generally valid, and a click-through "I agree" can bind.
• "Agreement to agree" is the classic trap. If the essential terms are left for later, there may be nothing certain to enforce — letters of intent often fall here.
• Proof and authority decide real cases. A verbal deal can bind but is hard to prove, and a contract signed without authority may not bind the company — so write it down and confirm who can sign.

Frequently asked questions

What makes a contract legally binding in Ontario?

A contract is legally binding in Ontario when a few core ingredients all come together: one party makes an offer, the other accepts it on those terms, both sides give something of value (consideration), and they intend to create legal relations. On top of that, the parties need the legal capacity to contract, the essential terms have to be certain enough to enforce, and the purpose has to be lawful. If any one of those is genuinely missing, you may have a conversation or a hope, but you do not have an enforceable contract. Most everyday business deals tick all the boxes without anyone thinking about it.

What are the essential elements of a contract?

In Ontario, courts generally look for seven things: (1) an offer; (2) acceptance of that offer on its terms; (3) consideration — each side gives something of value; (4) an intention to create legal relations; (5) capacity — the parties are legally able to contract; (6) certainty — the essential terms are clear enough to enforce; and (7) legality — the purpose and terms are lawful. The first four are the classic core people learn, but capacity, certainty, and legality matter just as much. A deal that has the first four but fails on certainty or legality is still not binding.

What is "consideration" and do I need it?

Consideration is the thing of value each side gives in a contract — money, goods, services, or a promise to do (or not do) something. It is the legal answer to "what is each party getting out of this?" Yes, you generally need it: a bare promise or a pure gift, with nothing given in return, is usually not an enforceable contract in Ontario. So "I promise to give you my old car for free" is not a contract you can enforce, but "I will sell you my car for $2,000" is. The amount does not have to be fair or large — it just has to exist.

Does a contract have to be in writing to be valid?

No — most contracts in Ontario do not have to be in writing. An oral (verbal) agreement can be fully binding if all the essential elements are there. There are important exceptions, though. Under the Statute of Frauds, certain contracts must be in writing to be enforceable — notably guarantees and contracts dealing with land or an interest in land (among a few others). And even where an oral contract is valid, the real-world problem is proof: if the other side denies the terms, you have to convince a court what was actually agreed. That is why I push clients to put deals in writing regardless.

Is a verbal contract binding in Ontario?

Often, yes. A verbal contract can be just as binding as a written one in Ontario, as long as it has offer, acceptance, consideration, intention, capacity, certainty, and a lawful purpose. The handshake deal is not automatically worthless. The catch is twofold: certain contracts (like guarantees and land deals) must be in writing under the Statute of Frauds, and for everything else the challenge is proving what was said. Memories differ, and "he said, she said" is a hard way to win. A verbal deal can bind you — which is exactly why you should be careful what you agree to out loud.

Is an email or text message a binding contract?

It can be. An exchange of emails or texts can form a binding contract if it contains all the essential elements — a clear offer, an acceptance, consideration, the intention to be bound, and certain terms. People are sometimes shocked to learn that a casual "yes, let's do it for $5,000" by email can lock them in. The medium is not what matters; the substance is. That said, loose, informal messages often leave essential terms vague or signal that the parties were still negotiating — which can mean no binding contract yet. Treat your business emails and texts as if they might end up in front of a judge.

Are electronic signatures legally valid in Ontario?

Generally, yes. Under Ontario's Electronic Commerce Act, electronic contracts and electronic signatures are valid in most situations. An agreement formed by email, or by clicking "I agree" on a website, can be a binding contract, and an electronic signature can satisfy a signing requirement. There are some exceptions — certain documents, such as wills, are carved out — but for the vast majority of commercial agreements, e-signature platforms and click-through acceptance are perfectly enforceable. The key is being able to show who signed and what they agreed to, which good e-signature tools are designed to capture.

What is an "agreement to agree" and why doesn't it bind?

An "agreement to agree" is a deal that leaves essential terms to be settled later — "we'll work out the price down the road" or "terms to be negotiated in good faith." Ontario courts often find these are not binding, because a contract needs certainty: if the essential terms are still open, there is nothing definite to enforce. Letters of intent and term sheets frequently fall into this trap, especially when they are meant to be non-binding placeholders. The fix is to nail down the essential terms — or to be deliberate about which parts are binding and which are not — rather than leaving the core of the deal for "later."

Can a contract be void or unenforceable?

Yes. Even something that looks like a contract can fail. It may be void or unenforceable if there is no consideration, if essential terms are missing or too vague (uncertainty), if it was really just an "agreement to agree," if there was no intention to be legally bound, if the person who signed lacked authority to bind the party, or if the purpose is illegal. Issues like a lack of capacity, misrepresentation, duress, or undue influence can also undo a contract. So "we signed something" is not the end of the inquiry — what you signed, and how, decides whether a court will actually enforce it.

Do I need a lawyer to make a contract binding?

No — you can form a binding contract without a lawyer, and people do it constantly. A lawyer is not a legal requirement for a contract to be enforceable. What a lawyer adds is certainty and protection: making sure the essential terms are clear, that the agreement says what you think it says, that nothing important is left as an "agreement to agree," and that the document holds up if a dispute arises. For a small, low-risk deal, a careful written agreement may be enough on its own. For anything significant — money, a long term, real risk — having it reviewed is usually cheaper than the dispute it prevents.

Final thoughts

"Is my contract legally binding?" almost always comes down to the same disciplined question: are the essential elements there? Offer, acceptance, consideration, intention, capacity, certainty, and legality. When all seven are present, you usually have an enforceable agreement — written or oral, on paper or by email. When one is genuinely missing, you may have a friendly understanding, but not a contract a court will help you enforce.

The good news is that the parts most likely to fail are the parts you control: nailing down the essential terms instead of deferring them, making sure both sides give value, confirming the person signing can actually bind the company, and putting the deal in writing — especially for the things the Statute of Frauds requires. Do those, and most of the traps in this guide never get the chance to bite. If a dispute has already started, a clear-eyed read on whether there is even a binding contract is the first move, and it shapes everything about how you enforce the contract in Ontario or what you can claim in breach of contract damages.

If you want a contract drafted so it actually holds up, or you are staring at a "deal" and are not sure it is one, a contract lawyer in Toronto can pressure-test it before it costs you. And if the relationship has already broken down, a contract dispute lawyer — or a business lawyer more generally — can tell you where you stand. Call 416-554-1639 or book a free consultation, and we can map it out in a short conversation.