According to those who do not consider khulʿ to be valid without compensation, if a husband and wife mutually agree to khulʿ without compensation, or if they were unaware of its necessity, does the khulʿ take effect as a divorce, or must it be redone with compensation?

According to the Hanafis, Shafi'is, and Hanbalis, khul' without compensation does not constitute khul', but rather a divorce if the husband intended divorce by it; otherwise, it is not considered anything. It is more prudent for the spouses, if they wish to perform khul', to do so with compensation, even if it is slight.