Legal Definitions - collateral condition

A collateral condition is a term used in contracts and legal instruments that requires the performance of an act that has no relation to the main purpose of the agreement. It is a future and uncertain event on which the existence or extent of an obligation or liability depends. For example, if Jones promises to pay Smith $500 for repairing a car, Smith's failure to repair the car relieves Jones of the promise to pay.

Another example of a collateral condition is a condition that requires the performance of an act having no relation to an agreement's main purpose. For instance, if a landlord promises to fix a tenant's roof, but only if the tenant agrees to mow the lawn, the tenant's failure to mow the lawn would relieve the landlord of the promise to fix the roof.

Collateral conditions are different from essential conditions, which are conditions that go to the root of the contract and are necessary for the performance of the agreement. Collateral conditions are not essential to the performance of the agreement, but they may affect the parties' obligations under the contract.