1. Voidable Contract: An agreement which is enforceable by law at the option of one or more of the parties thereto, but not at the option of the other or others, is a voidable contract. A contract is voidable when one of the parties to the contract has not exercised his free consent. One of the essential elements of a formation of a contract for example, free consent, is absent. All voidable contracts are those which are induced by coercion fraud or misrepresentation. The person whose consent is not freely given may avoid a contract. It therefore continues to be valid till the party whose consent is caused by coercion, undue influence, fraud or misrepresentation choose to avoid the contract within a reasonable time. Contract then is not binding on the other party.
2. Void Contract: A contract which ceases to be enforceable by law becomes void, when it ceases to be enforceable. A void contract is a nullity from its inception. No rights accrue there under. A contract may also be originally valid when entered into but subsequently due to change in the events or circumstances, it may become void. It should be noted that there cannot be a void contract because when the contract is void, it is no contract at all. The right expression therefore is void agreement and not void contract.
3. Unenforceable Contract: A contract which cannot be enforced is a valid contract in law, but is incapable of proof, and therefore cannot be enforced in the Court of Law.
4. Executed Contract: Where both the parties have performed their obligation, it is an executed contract. Even when one party to the contract has performed his share of the obligation, the contract is executed though to the other party is still under an outstanding obligation to perform his part of the promise.
5. Executory Contract: Here neither party to the contract has performed his share of the obligation, for example, both the parties have yet to perform their promises, the contract is executory. In an executed contract one party has already performed his part of he agreement while the other party has to perform his par. In an executory contract both the parties have to perform their mutual promises and the fact that they have to perform their parts of the contract does not affect the validity of the contract.
6. Express Contract: When the terms of a contract are reduced in writing or are agreed upon by spoken words at the time of its formation, the contract is express.
7. Implied Contract: The terms of a contract are inferred from the conduct or dealing between the parties. When the proposal or acceptance of any promise is made otherwise than in words, the promise is said to be implied. Such an implied promise leads to an implied contract. For example, A boards a bus. It is implied from his conduct that A has entered onto an implied promise to purchase a ticket.
8. Quasi-Contract: Certain relations resemble those created by a contract. Certain obligations which are not contracts in fact but are so in the contemplation of law. These are called Quasi-Contracts.
‘A’ supplies necessities to ‘B’ who is not capable of contracting and reimbursing to ‘A’. A is entitled to be reimbursed from B’s property.
Quasi contracts raise out of obligation enjoyed by one person from the voluntary acts of the other which are not intended to be performed gratuitously
9. Contingent Contract: A contingent is one in which a promise is conditional and the contract shall be performed only on the happening of some future uncertain event.
‘A’ contracts to pay B Rs 10,000, if B’s house is burnt. This is a contingent contract.
10. Contracts of Record: A contract of record is one which is taken to the records of a Court, for example judgment of a court. Such judgments create a binding effect through the authority of the Court.
11. Specialty Contract: A specialty contract is a contract which is in writing signed, sealed and delivered by the parties. It is also called a contract under seal. Consideration is not necessary in a specialty contract.
12. Simple Contract: A simple contract s one which is not under seal. All contracts which are not under seal are simple contracts. All simple contracts require consideration. They may be made by written or spoken words. Contracts of Record and Specialty Contracts are also known as Formal Contracts. The classification of contracts into Contracts of Record, Specialty and simple is under the English Law. Indian Law does not recognize contracts without consideration. All contracts must have consideration in order the valid subject to exceptions under section 25 of the Act.
13. Statutory Contract: When all or some of the terms and conditions of contract are statutory then the entire contract, or that extent as the case may be, would be regarded as statutory contract.