Contracts may generally be formed without the necessity for any formalities, other than the elements of contract formation (such as offer, acceptance, consideration and intention). See Offer, Acceptance, Consideration, and Intention to create legal relations. However, formalities are required for certain types of contracts. The source of such requirements is usually statute, and the principal example is in the case of contracts for sale or disposition of land or interests in land. Formalities in such cases will deal principally with identifying the parties, property and price, and making sure the party against whom the contract is sought to be enforced has signed the contract. In some cases, the written formalities will need to take the form of a deed.

Contracts or agreements by deed provide the main way in which promises unsupported by consideration may be enforced. This is because the mandated form takes the place of consideration. It is the equivalent of the historical solemn promise under seal. Deeds must satisfy formalities of form, execution and delivery in accordance with statutes that provide for the transfer of land by deed.

Breach of agreement or promise by deed is remedied by damages at common law and under statute, but equitable remedies are generally not available where the promise is gratuitous.

Deeds should be used where there is doubt about the provision of sufficient consideration or where no consideration has been provided. An important example of the use of deeds in circumstances where no consideration is given is deeds of release. These are deeds that are commonly used to resolve a dispute over the performance or breach of a contract. The party in breach promises to pay an amount or perform an act in exchange for the other party’s promise not to take legal action. The deed discharges and supersedes the breached contract. See Deeds of release. However, deeds may be used in other cases as well because they provide strategic and evidentiary advantages in the event of dispute. See Deeds.

Legal advisers should recognise that some contracts must be in writing to be enforceable, while others will be considered unenforceable if they are not evidenced in some way by writing of some kind. One kind of contract that must be written is a formal contract. These are formal, written contracts that must comply with a mandated form, such as deeds. Others that remain simple contracts, but must be in writing, are those in respect of which there exists a statutory requirement of writing. The most notable example is a contract for sale or disposition of land or interest in land, which has, in most jurisdictions, inherited the principle derived from the UK, which is that a court will not enforce a contract for sale of land unless it is in writing, or unless there is a written note or memorandum of it in writing, that is signed by the party to be charged with the contract or their authorised agent. Non-compliance with this key provision makes the contract unenforceable unless an equitable remedy is available, such as a remedy by way of the doctrine of part performance. See Contracts required to be in writing.

Courts exercising equitable jurisdiction may provide relief in cases where the statutory requirements of writing have not been met but where, according to the maxims and principles of equity, an applicant demonstrates convincing evidence of an oral contract for sale of land. The applicant must be able to demonstrate post-contractual acts that were performed in reliance on the agreement, that were permitted by the oral contract and that were unequivocally referable to the type of contract that is being alleged. See Part performance.