In contract law, the performance of existing duties generally does not qualify as valid consideration for a new agreement. Here are some key aspects of the performance of existing duties:
Performance of an existing duty: If a party is already under a legal duty to perform an act or provide a service, then that performance does not constitute valid consideration for a new agreement.
Duty to perform: The duty to perform may arise from a prior contract or agreement, or from a legal obligation, such as a duty imposed by law or by a professional code of ethics.
Exceptions: There are some exceptions to the rule against performance of existing duties, such as if the performance involves additional work or expense that was not originally contemplated by the parties, or if the performance of the duty is done in a different manner or at a different time than originally agreed upon.
Adequacy of consideration: Even if the performance of an existing duty is considered valid consideration, it may not be considered adequate consideration if the value of the performance is already owed by the promisor.
Overall, the performance of existing duties generally does not qualify as valid consideration for a new agreement in contract law. However, there are some exceptions to this rule, and even if the performance is considered valid consideration, it may not be adequate if the value of the performance is already owed by the promisor.