Is an MOU Legally Binding? MOU vs Contract Explained

An MOU (memorandum of understanding) is not legally binding when the parties make clear that it is not, and that is how most MOUs are meant to work: they record the intended deal while the final contract is negotiated. But the title alone does not decide it. If the MOU’s wording and the parties’ conduct show they agreed on the essential terms and intended to be bound, a court or tribunal may treat all or part of it as a contract under the law that governs it. Write the MOU so that it says which clauses bind and which do not.

Is an MOU legally binding?

It depends on what it says and on the governing law, not on its name. Three examples of how legal systems approach it:

Governing law or instrument	Rule
Taiwan, Civil Code	A contract is formed when the parties express concordant intent; if they agree on all essential elements, it is presumed formed even if non-essential points are open (Art. 153). If they agreed the contract must be made in a certain form, it is presumed not formed until that form is completed (Art. 166).
UNIDROIT Principles 2016	If a party insists that there is no contract until agreement on specific matters or in a particular form, none is concluded before then (Art. 2.1.13). But parties who intend to be bound can leave terms open for later agreement and still have a contract (Art. 2.1.14).
England and Wales	Whether a binding contract exists depends on what the parties communicated by words and conduct, judged objectively, not on their private intentions. In RTS Flexible Systems v Molkerei Alois Müller [2010] UKSC 14, the Supreme Court held the parties had become bound on agreed terms despite a “subject to contract” clause, because their conduct showed they had waived it. The court’s moral: agree first and start work later (judgment).

Under the UNIDROIT Principles 2016, no particular form is needed for a contract (Art. 1.2), so a document called an MOU can be enough if the other conditions are met.

MOU vs contract vs LOI: what is the difference?

The labels describe intention, not legal effect. A letter of intent (LOI), a memorandum of agreement (MOA) and a term sheet raise the same question as an MOU: did the parties agree terms and intend to be bound?

Document	Usually used for	Binding?
MOU	Recording a shared plan before negotiating the final contract, often between several parties	Usually not, apart from clauses stated to bind
Letter of intent / term sheet	Setting out the main commercial terms of a proposed deal	Usually not, apart from clauses stated to bind
Memorandum of agreement (MOA)	Recording agreed terms, often for cooperation or a defined project	Often intended to bind; check the wording
Contract	The final, complete agreement	Yes, if validly formed

Which MOU clauses should be binding?

Make the clauses that protect you during negotiations binding, and say so expressly. Typical candidates:

• Confidentiality of information exchanged during talks;
• Exclusivity for a set period, if one party is giving up other options;
• Costs: each party bears its own unless agreed otherwise;
• Governing law and dispute resolution for the binding clauses;
• Termination of the MOU and of any exclusivity.

Then add a clear statement that everything else, including the commercial terms, is not binding and that no contract exists until a final agreement is signed. Without a binding confidentiality clause you rely on narrower default rules: the UNIDROIT Principles impose a duty not to disclose or misuse information given as confidential during negotiations (Art. 2.1.16), and Taiwan’s Civil Code makes a party liable if it intentionally or grossly negligently discloses a secret it was asked to keep, even when no contract is formed (Art. 245-1).

Can you be liable for walking away from an MOU?

Usually not for failing to agree, but possibly for negotiating in bad faith. The UNIDROIT Principles say a party “is free to negotiate and is not liable for failure to reach an agreement”, but one who negotiates or breaks off negotiations in bad faith is liable for the losses caused, for example by negotiating with no intention of reaching agreement (Art. 2.1.15). Taiwan’s Civil Code imposes similar pre-contract liability for concealing or misrepresenting material facts in bad faith when asked, or other conduct obviously against good faith (Art. 245-1); the claim expires after two years. Which rule applies depends on the law governing the MOU: in Taiwan, the parties’ chosen law applies, otherwise the most closely connected law (Act Governing the Choice of Law in Civil Matters Involving Foreign Elements, Art. 20). So choose it in the MOU.

Can an MOU support a licence application?

Sometimes, but only the regulator’s own checklist tells you whether an MOU is enough. Gaming and other licence applications typically ask how the business will operate, including who will supply key systems. When the licensed company does not exist yet, operators sometimes sign an MOU or letter of intent with a platform or payment provider, to be replaced by a full agreement once the licence is granted. Before relying on one:

• check whether the regulator accepts an MOU or LOI, or requires a signed agreement;
• check that the supplier holds any licence it needs; some regulators license B2B suppliers separately (see the jurisdiction comparison);
• make sure the binding clauses (confidentiality, exclusivity, timing) match the licensing timeline.

Frequently asked questions

Can conduct turn a non-binding MOU into a contract?

It can. If the parties start performing as though the deal were agreed, a court may find that a contract exists on the terms they acted on, as in the RTS case.

Should an MOU be signed by authorised signatories?

Yes. Even a non-binding MOU usually contains binding clauses, so have it signed by people with authority to bind each company.

How long should an MOU last?

Give it an end date or a long-stop date, after which the MOU and any exclusivity lapse unless the parties extend them in writing. A contract review can check that the binding and non-binding parts are clearly separated; for the clauses the final contract will need, see the essential clauses every business contract needs.