§ 2033.300.Withdrawal of or amendment to admission; authority and discretion of court

An admission is powerful precisely because Section 2033.410 treats it as conclusively established, which is why this section keeps withdrawal or amendment on a short leash. A party cannot change an earlier admission on its own by serving a corrected response; withdrawal or amendment requires leave of court, granted only after notice to every other party in the case, so the change happens in the open rather than quietly.

The court can grant that leave only on two findings working together. First, the original admission has to be the product of mistake, inadvertence, or excusable neglect, not a considered position the party is trying to escape once it turns out to be inconvenient. Second, the party who obtained the admission must not be substantially prejudiced in maintaining its action or defense on the merits if the withdrawal is allowed, a safeguard against a late change that would blindside the other side after it has built its trial strategy around the admission standing. Even when the court allows the change, it can attach conditions that are just, including letting the party who obtained the original admission pursue additional discovery into the withdrawn or amended matter, and requiring the party making the change to bear some or all of the cost of that additional discovery.