Excuse by Failure of a Presupposed Condition

Excuse by Failure of a Presupposed Condition occurs when a contract is based on an assumption that a specific condition will happen, but that condition fails to materialize. This means that if both parties believed that a certain event or circumstance was true when making the agreement, and that belief turns out to be incorrect, the affected party may be excused from fulfilling their obligations under the contract. Essentially, the deal relies on something that wasn't guaranteed, and when that expectation fails, it can legally justify non-performance of the contract.