Bilateral and unilateral contracts … bite size
A bilateral contract is a contract where both parties to the contract are obliged to do something.
In a contract to sell goods, one party is obliged to provide the goods and the other party is obliged to pay some money. In a contract to perform a service, one party is obliged to provide the service and the other party is obliged to pay some money.
A unilateral contract is a contract where only one party to the contract is obliged to do something.
Reward cases are good examples of unilateral contracts. One party to the contract offers a reward of £100 to anyone who finds their lost dog but no one is obliged to find the lost dog.
Another example of a unilateral contract is the contract between a property owner and an estate agent. The property owner is obliged to pay the estate agent a fee if they find someone to buy the property. However, the estate agent is not obliged to find someone to buy the property (they will not be breaching the terms of the contract by failing to find someone to buy the property).
Great Northern Railway Co v Witham (1873)