A. AMENDMENTS. A party may amend his or her pleading once as a matter of course at any time before a responsive pleading is served or, if the pleading is one to which no responsive pleading is permitted and the action has not been placed upon the trial calendar, he or she may so amend it at any time within twenty (20) days after it is served. Amendments to add omitted counterclaims or to add or drop parties may be made as a matter of course within the time specified above. Otherwise a party may amend the pleading only by leave of court by submitting the proposed amendment with the motion for leave of court or by written consent of the adverse party; and leave shall be freely given when justice so requires. A party shall respond to an amended pleading within the time remaining for response to the original pleading or within twenty (20) days after the service of the amended pleading, whichever period may be longer, unless the court otherwise orders.
§ 2015.Amended and Supplemental Pleadings
Chapter 39: Oklahoma Pleading Code · Last amended November 1, 2022 · Last verified August 3, 2026
In one sentenceSection 2015 lets a party amend a pleading once as a matter of course before a response is served, requires leave of court for later amendments, and sets when an amendment, including one changing a defendant's identity, relates back to the original filing date.
Full Text of § 2015
B. AMENDMENTS TO CONFORM TO THE EVIDENCE. When issues not raised by the pleadings or by the pretrial conference order, where the order has superseded the pleadings, are tried by express or implied consent of the parties, they shall be treated in all respects as if they had been raised in the pleadings or the pretrial conference order. Such amendment as may be necessary to cause the pleadings or the pretrial conference order to conform to the evidence and to raise these issues may be made upon motion of any party at any time, even after judgment; but failure so to amend does not affect the result of the trial of these issues. If evidence is objected to at the trial on the ground that it is not within the issues made by the pleadings or the pretrial conference order, the court may allow the pleadings or the pretrial conference order to be amended and shall do so freely when the presentation of the merits of the action will be served thereby and the objecting party fails to satisfy the court that the admission of such evidence would prejudice him or her in maintaining the action or defense upon the merits. The court may grant a continuance to enable the objecting party to meet such evidence.
Where the pretrial conference order has superseded the pleadings, it is sufficient to amend the order and the pleadings shall not be amended.
C. RELATION BACK OF AMENDMENTS. An amendment of a pleading relates back to the date of the original pleading when:
1. Relation back is permitted by the law that provides the statute of limitations applicable to the action; or
2. The claim or defense asserted in the amended pleading arose out of the conduct, transaction, or occurrence set forth or attempted to be set forth in the original pleading; or
3. The amendment changes the party or the naming of the party against whom a claim is asserted if paragraph 2 of this subsection is satisfied and, within the period provided by subsection I of Section 2004 of this title for service of the summons and petition, the party to be brought in by amendment:
a. has received such notice of the institution of the action that he or she will not be prejudiced in maintaining a defense on the merits, and
b. knew or should have known that, but for a mistake concerning the identity of the proper party, the action would have been brought against him or her.
An amendment to add an omitted counterclaim does not relate back to the date of the original answer. The delivery or mailing of process to the Attorney General of Oklahoma, or an agency or officer who would have been a proper defendant if named, satisfies the requirements of subparagraphs a and b of this paragraph with respect to the State of Oklahoma or any agency or officer thereof to be brought into the action as a defendant.
D. SUPPLEMENTAL PLEADINGS. Upon motion of a party the court may, upon reasonable notice and upon such terms as are just, permit the party to serve a supplemental pleading setting forth transactions or occurrences or events which have happened since the date of the pleading sought to be supplemented. Permission may be granted even though the original pleading is defective in its statement of a claim for relief or defense. If the court deems it advisable that the adverse party plead to the supplemental pleading, it shall so order, specifying the time therefor. A supplemental pleading relates back to the date of the original pleading if it arises out of the conduct, transaction, or occurrence set forth in the original pleading.
Amendment History
Amended by Laws 2022, c. 60, s. 1, eff. 11/1/2022. Amended by Laws 2018, c. 37, s. 1, eff. 11/1/2018. Added by Laws 1984, SB 417, c. 164, §15, eff. 11/1/1984. Amended by Laws 1993, HB 1468, c. 351, §3, eff. 9/1/1993.
Plain-English Summary
A party may amend a pleading once without asking permission, any time before a responsive pleading is served, or, if no response is allowed and the case hasn't been set for trial, within twenty days after it's served. Amendments adding an omitted counterclaim or adding or dropping parties get the same as-of-course treatment within that window. Beyond that, amendment requires either the court's leave, freely given when justice so requires, with the proposed amendment submitted alongside the motion, or the opposing party's written consent.
When an issue outside the pleadings gets tried anyway because both sides implicitly or expressly go along with it, subsection B treats that issue as if it had been pleaded from the start, and either side can move, even after judgment, to amend the pleadings to match what was tried. A party who objects to evidence as outside the pleadings can still see the pleadings amended over that objection if allowing it serves the merits and doesn't prejudice the objecting party, though the court can grant a continuance to let that party respond to the new evidence.
Subsection C sets three routes to relation back: the statute of limitations governing the claim allows it, the amendment arises from the same conduct, transaction, or occurrence already set out in the original pleading, or the amendment corrects the identity of a defendant, so long as the new defendant got timely notice of the suit within the service window under subsection I of Section 2004 and knew or should have known the suit would have named them but for a mistake. An amendment adding an omitted counterclaim never relates back. Subsection D covers supplemental pleadings, adding events that happened after the original pleading was filed, permitted on motion and reasonable notice, and relating back to the original pleading's date if the new material arises from the same conduct, transaction, or occurrence already pleaded.
Frequently Asked Questions
Can a party amend a pleading without asking the court's permission?
Yes, once, as a matter of course, any time before a responsive pleading is served, or within twenty days if no response is required and the case isn't yet on the trial calendar, under subsection A.
What happens if an issue not in the pleadings gets tried at trial anyway?
Under subsection B, if both sides expressly or impliedly consented to trying it, the issue is treated as if it had been pleaded, and either party may move to amend the pleadings to match the evidence, even after judgment.
When does an amendment "relate back" to the date of the original pleading?
Under subsection C, when the governing statute of limitations allows it, when the new claim or defense arises from the same conduct or occurrence already pleaded, or when it corrects a defendant's identity and that defendant had timely notice and knew or should have known about the mistake.
What's a "supplemental pleading," and is it different from an amendment?
A supplemental pleading, addressed in subsection D, adds transactions or events that happened after the original pleading was filed, rather than correcting or adding to what already existed; it requires a motion and reasonable notice, and relates back if it arises from the same conduct already pleaded.
Source & verification. Section text is reproduced verbatim from
Title 12 of the Oklahoma Statutes, enacted by the Oklahoma Legislature.
Last verified August 3, 2026.
· Official source
Also known as: oklahoma amended pleading rule12 O.S. § 2015relation back amendment oklahomaoklahoma FRCP 15 equivalent