It is easy to get these two mixed up, but there are several key distinctions that make proper identification of misnomer versus misidentification essential for understanding (1) the significance of the opposing party's mistake and (2) what to do if presented with such a mistake.
What's the difference?
In the simplest (and most common) circumstances, misnomer occurs when a plaintiff serves the correct defendant under an incorrect name. Barth v. Bank of Am., N.A., 351 S.W.3d 875, 876-77 (Tex. 2011). In contrast, misidentification occurs when a plaintiff serves an incorrect entity, i.e. one with zero interest in the suit. Chilkewitz v. Hyson, 22 S.W.3d 825, 828 (Tex. 1999).
Why does it matter?
1. Statute of Limitations
If the mistake is misnomer, the applicable limitations period is tolled and an amended petition identifying the defendant's correct name relates back to the date the original petition was filed. See Enserch Corp. v. Parker, 794 S.W. 2d 2, 4-5 (Tex. 1990).
On the other hand, misidentification generally does not toll the applicable limitations period. Continental Southern Lines Inc. v. Hilland, 528 S.W.2d 828 (Tex. 1975); Womack Machine Supply Co. v. Fannin Bank, 499 S.W.2d 917, 919 (Tex. Civ. App. [14th Dist.] 1973), rev'd on other grounds, 504 S.W.2d 827 (Tex. 1974). Additionally, in a situation of misidentification, there is no duty on the correct entity to point out the error or intervene in the case. Matthews Trucking Co. v. Smith, 682 S.W. 2d 239 (Tex. 1984). Thus, courts have consistently held that a personal injury suit is properly barred as a matter of law based on limitations where a plaintiff misidentifies someone other than the intended defendant in the original petition and fails to amend and serve the proper defendant prior to the expiration of the statute of limitation. See Marez v. Moeck, 608 S.W.2d 740, 742 (Tex. Civ. App.-Corpus Christi 1980, no writ) (limitations barred negligence suit against driver of vehicle when original suit brought only against driver's father and driver was not named or served until after the two-year statute of limitations period had run).
Texas recognizes a limited exception to the general rule against tolling in a misidentification case. Tolling may be permitted only if: (1) there are two separate but related entities using a similar name, (2) the correct entity had notice of the suit, and (3) the correct entity was neither misled nor prejudiced by the mistake. Flour Bluff ISD v. Bass, 133 S.W. 3d 272, 274 (Tex. 2004).
2. Void Judgment
Rule 124 of the Texas Rules of Civil Procedure provides that no judgment can be rendered against a defendant without proper service. This rule is generally not an issue in misnomer cases as the correct defendant is served, even if service occurred under the incorrect name. Wilkins v. Methodist Health Care Sys., 108 S.W. 3d 565, 570 (Tex. App. - Houston [14th Dist.] 2003, rev'd on other grounds, 160 S.W. 3d 559 (Tex. 2005). However, in the context of misidentification, this Rule raises the possibility of dismissing all claims and/or voiding any judgment entered if the plaintiff fails to complete service of citation on the correct entity once discovering his or her mistake. Id. at 570-72.
What to do?
As you can imagine, addressing misnomer versus misidentification requires vastly different approaches.
If the mistake is misnomer, sometimes the most efficient course of action will be a simple phone call or letter to the opposing attorney identifying the problem. If opposing counsel is uncooperative, consider filing a Motion to Abate. Do not wait for the mistake to be corrected before filing a timely answer, and be sure to explain the misnomer in your answer.
If the mistake is misidentification, and your client is not a proper party, file a Verified Denial. If opposing counsel does not promptly dismiss the misidentified entity from the case, follow up with a Motion for Summary Judgment. Keep in mind that in a misidentification case the correct entity has no duty to intervene, and the burden is on the plaintiff to serve the correct entity once the misidentification is discovered.