A promise to do something that you are already obligated to do is generally a valid consideration.

Question

Quizplus · Accepted Answer

Consideration requires that something of value (including a benefit, right, interest, or profit) be exchanged between the parties. A promise to do something that one is already legally obligated to do does not constitute new consideration because it does not provide any additional benefit to the promisor or impose any additional detriment on the promisee.

A Promise to Do Something That You Are Already Obligated