A contract is, at its core, a promise the law will enforce. If one side breaks that promise, the other side is entitled to a remedy. Before we review or draft any agreement for a client in Cook County, we ask the same question a court would ask: does this document actually contain everything needed to make a promise legally binding?
Legal writers describe the required pieces differently, but in our practice we walk clients through seven elements that give the fullest, most practical picture of the elements of a valid contract: capacity, offer, acceptance, consideration, mutual agreement, legality, and proper form. This guide covers each one with a plain-English explanation and real examples, so you know what to look for the next time you’re asked to sign an agreement in Chicago.
What Is a Contract, Legally Speaking?
Strip away the legalese, and a contract is simply a promise the law is prepared to enforce, with a remedy available if that promise is broken. That single idea is the foundation for everything else in contract law.
Sources disagree on exactly how many "elements" make up an enforceable promise. Some frameworks describe six elements, focusing on offer, acceptance, consideration, capacity, awareness and legality, as Thomson Reuters explains in its overview of contract essentials. Others expand the list to include intention to create legal relations and certainty of terms, as outlined by Legal Sifter’s breakdown of contract elements, while still others frame it around seven categories that include "meeting of the minds" and "terms of the contract" as separate items, as Concord’s contract guide describes. None of these lists is wrong; they simply organize the same underlying requirements differently. In our practice, we use the seven-element version below because it matches how disputes actually play out in Cook County courts.
The Elements of a Valid Contract, Explained
Capacity. Every person signing a contract must be of legal age and mentally competent, meaning they are able to understand and be bound by the promise they are making. As the video explains, this element also covers artificial persons such as corporations, LLCs and partnerships, where the question shifts from age to authority: does the person signing on the entity’s behalf actually have the power to bind it? This comes up constantly in our corporate practice, where an unauthorized signature can unravel an otherwise well-drafted agreement.
Offer. An offer is a manifestation of willingness to enter into a bargain, made in a way that invites the other side to accept and close the deal. A well-known illustration is Carlill v Carbolic Smoke Ball Company, in which a company advertised a cash reward if its product failed to prevent flu, then argued in court that the advertisement was never a serious offer at all. Courts disagreed, and the case remains a touchstone for how far an "offer" can extend, even into advertising language.
Acceptance. Once there is an offer, acceptance has to match it exactly: under classical contract principles, it must be an unconditional, mirror-image agreement to the offer’s terms. If someone offers to sell a car for a set price and the other party agrees to buy it at a different price, that is not acceptance, it is a counteroffer.
Consideration. Consideration is what each side gives up in exchange for the other’s promise. It has two components worth understanding: whether the person receiving the promise incurred a genuine legal detriment, and whether that detriment was actually bargained for rather than incidental to the deal. In plain terms, both sides need to give something up, and that exchange has to be the reason the promise was made in the first place.
Meeting of the Minds in Contracts
Mutual agreement means both parties share the same understanding of what they are actually promising. It sounds obvious, but disputes over this element come up constantly in real transactions, including some we see in Cook County real estate and business matters.
In our video, we walk through a classic illustration of two farmers who struck a deal for what both believed was a sterile cow, only to discover the animal was pregnant. The point is not the specific case but the principle it illustrates: if the parties were never truly agreeing on the same thing, there is no meeting of the minds, and no amount of signatures will make the agreement enforceable.
Legality and Proper Form
A contract also has to be legal in its purpose, in how it was procured, and in how it is carried out. A contract for an illegal purpose, or one obtained through bribery, will not be enforced no matter how carefully the paperwork is drafted.
Proper form asks a different question: does this particular agreement need to be in writing? Most contracts can be entirely oral. But certain categories are the exception, and some agreements, including real estate transactions and debt guarantees, must be in writing to be enforceable under what is known as the statute of frauds. This is precisely why every real estate closing we handle involves a signed written agreement rather than a handshake deal, and it is one of the reasons our closing checklist for Chicago home buyers treats the written contract as the starting point of the whole transaction.
Do Verbal, Email or Online Agreements Count?
A common misconception is that only a formally printed, signed document is a "real" contract. In fact, verbal and implied contracts can be legally valid as long as they contain the essential elements, such as when a contractor begins work immediately after a verbal agreement on scope and price.
The same logic extends to modern communication. Courts have repeatedly treated email chains and even text messages as enforceable agreements when those messages show offer, acceptance and consideration, and both sides clearly intended to be bound. Online transactions raise a related but distinct question: whether the website reasonably communicated that clicking a button such as "Purchase" would create a binding commitment, an issue recent circuit court decisions have addressed directly. The format of an agreement matters far less than whether the substance of all seven elements is actually present.
What Happens When Contract Elements Are Missing
If even one required element is missing, the contract may be void or unenforceable entirely. That is a serious consequence for anyone who assumed they had a deal.
There are, however, some narrow exceptions worth knowing about. Under the doctrine of promissory estoppel, courts will sometimes enforce a promise even without traditional consideration when the promisor should have reasonably expected the promise to induce action, that action was actually taken, and injustice can only be avoided by enforcing the promise. Form matters less than substance too: in the well-known case of Lucy v. Zehmer, a Virginia court upheld a contract written on a restaurant napkin because it showed genuine mutual assent and consideration, despite its informal appearance.
Context also shapes how courts read intent. Social and family arrangements are generally presumed not to carry legal intent, while commercial and business agreements are presumed to be legally binding unless there is evidence to the contrary. That presumption matters in disputes between family members over informal promises, and it cuts the other way in business dealings, where courts start from the assumption that the parties meant what they signed.
Why This Matters Before You Sign Anything in Chicago
Whether you are reviewing a residential lease, a home purchase agreement, or a commercial contract, missing even one of these seven elements can leave you without a remedy if the other side backs out. A purchase agreement with an unclear offer, an ambiguous acceptance, or no real consideration on one side is not just poorly written, it may not be enforceable at all.
In our real estate practice, we walk you through every clause in a purchase or lease agreement in plain English before closing, so the offer, acceptance and consideration are clearly documented and there are no surprises at the closing table. For business owners, contract drafting and negotiation is core to what our corporate and business law team handles, from initial formation through commercial disputes. In every practice area, we offer a free consultation and a transparent, upfront fee structure, so you understand your options before a contract dispute ever reaches litigation.
Key Takeaways
- A contract is a legally enforceable promise, not just a handshake or a good-faith understanding.
- The seven core elements are capacity, offer, acceptance, consideration, mutual agreement, legality, and proper form.
- Missing even one element can make a contract void or unenforceable, though promissory estoppel can sometimes fill a gap where consideration is absent.
- Verbal, email and even online agreements can be binding if they meet all the essential elements and show clear intent to be bound.
- Certain contracts, such as real estate transactions and debt guarantees, must be in writing under the statute of frauds regardless of the other elements being present.
FAQ
What are the seven elements of a valid contract?
The seven elements are capacity (the parties are legally able to contract), offer (a clear manifestation of willingness to make a deal), acceptance (an unconditional agreement to the offer’s exact terms), consideration (something of value exchanged by each side), mutual agreement (both parties share the same understanding of the deal), legality (the purpose, procurement and performance are all lawful), and proper form (the agreement is in writing when the law requires it).
Can a contract be valid if it’s only verbal?
Yes. Most contracts can be entirely oral and still be enforceable, as long as they contain all the essential elements. The exceptions are specific categories the statute of frauds requires to be in writing, including real estate transactions and guarantees of someone else’s debt.
What happens if a contract is missing an element like consideration?
Without consideration, an agreement is generally not an enforceable contract and may be treated as void. That said, courts sometimes still enforce a promise under the doctrine of promissory estoppel when someone reasonably relied on that promise to their detriment and enforcing it is the only way to avoid an injustice.
Is a text message or email exchange a binding contract?
It can be. Courts have enforced email chains and text message exchanges as valid contracts when the messages show a clear offer, acceptance and consideration, and both parties’ words and conduct show they intended to be bound by the exchange.
Do I need a lawyer to review a contract before I sign it?
It isn’t always required, but a plain-English review can catch a missing element or an unclear term before it becomes a costly dispute later. We offer a free consultation across all 18 of our practice areas in Chicago and Cook County, so you can have a contract reviewed and understand your options before you sign.