There is a split in authority as to whether errata may be used to make substantive changes to deposition testimony. The Ninth Circuit has ruled against making substantive changes.
Asia Vital Components Co., LTD. (“AVC”) ran afoul of that ruling by including nearly two dozen substantive changes in its errata, including changing “yes” to “no,” changing the names of various corporate entities, and changing some key words. The Court agreed with the opposing party’s assertion that the changes appeared designed “to limit AVC’s exposure in the United States by, for example, presenting AVC’s offices in Fremont as belonging to a separate entity… altering customer names, shipping location (from U.S. to Hong Kong), and the names of the products sold in the U.S., and changing ‘shipped’ to ‘sold’ so that AVC can attempt to escape liability due to importation of the accused AVC products into the U.S.” But even without any improper motive, the changes were not permissible. Regardless of intent, errata that contradict the original deposition testimony are not allowed.
Notably, the court held that the procedural posture did not matter. AVC argued that because the relevant portions of the deposition were not cited in any motion, and the deadline for dispositive motions had passed, there was nothing to strike. AVC claimed that the rule prohibiting substantive changes should be applied “only in the summary judgment context, where substantive changes to a deposition transcript might be used as a ‘sham’ to create an issue of fact.” The Court disagreed by quoting the seminal Ninth Circuit decision on this issue, Hambleton Bros. Lumber Co. v. Balkin Enterprises, Inc.:
Rule [30(e)] cannot be interpreted to allow one to alter what was said under oath. If that were the case, one could merely answer the questions with no thought at all then return home and plan artful responses. Depositions differ from interrogatories in that regard. A deposition is not a take home examination.
Deponents in the Northern District of California should be mindful of the Ninth Circuit authority that “Rule 30(e) is to be used for corrective, and not contradictory, changes.” Changes to substance that can be plausibly explained as transcription errors (for example, dropping a “not”) may be permissible, but anything beyond that is prohibited. In practice, most of the cases in the District where errata have been stricken are fairly egregious, and include dozens of contradictory answers, including changing “yes” to “no” and vice versa.
Deponents and parties who do not exercise care with errata risk a (successful) motion to strike.
 Asia Vital Components Co., Ltd. v. Asetek Danmark A/S, Case No. 3:16-cv-07160-JST (RMI) (“Asia Vital”), Dkt. 213 at 2 (N.D. Cal. Jan. 10, 2019).
 Id. at 1.
 Id. at 2 (citing Teleshuttle Techs. LLC v. Microsoft Corp., No. C04-02927 JW(HRL), 2005 WL 3259992, at *2 (N.D. Cal. Nov. 29, 2005)).
 Id. at 2 (quoting Hambleton Bros. Lumber Co. v. Balkin Enterprises, Inc., 397 F.3d 1217, 1225 (9th Cir. 2005)).
 Hambleton Bros., 397 F.3d at 1226.
 E.g., Teleshuttle Techs.; Parker v. Comcast Cable Commc’ns Mgmt., LLC, No. 315CV05673-THE-KAW, 2017 WL 1758086 (N.D. Cal. May 5, 2017).