What Happens If the Wrong Name Is Used in a Lawsuit?
Correcting or Amending a Name Is Commonly Allowed With Some Exceptions
Mistake of name in a lawsuit is fairly common and usually only a minor concern that is easily corrected. It happens usually become a person sued is known by a nickname or middle name and until the lawsuit is underway, details of the formal legal name of the person were unknown. It also happens when suing a business as it is common that a business will actually have various operating names or company divisions and it is difficult to know at the outset of a lawsuit which is the correct name or entity that should be involved. Although corrections of names is usually done, getting the name right in the beginning does help save time and money.
Generally, the law including rules of litigation permit reasonable corrections as necessary. A correction is often made merely on Consent of the parties to the legal case; however, if a party is unwilling to Consent, a Motion Hearing for review of the error and a decision by a Judge may be required. At a Motion Hearing, the Judge will consider whether the name correction should be allowed. Where the person resisting the correction, usually the person who will become properly named by the correction, the Judge typically reviews whether that person ought to know that the lawsuit, containing an improper name, was actually about that person and that involvement as a party to the case should be without surprise. This process is referred to as a Motion to Amend a misnomer on a nunc pro tunc basis which is just legal speak for correcting an incorrect name as if the name was proper from the very beginning.
The Case Law
If a Judge is needed to review and consider whether a name correction should be allowed, the Judge will look at whether the person whose name is sought for change knew, or ought to know, that the 'litigating finger' was pointed towards them the whole time. Essentially, if the lawsuit names "Bob", and Bob is later discovered as a merely short name for Robert, the Judge will review whether Bob knew that "Bob" meant Robert. If the facts indicate that Bob would know all along that Bob was the person being sued, just being sued under the incorrect name of "Bob" rather than the legally proper name of Robert, then it is highly unlikely that Bob will be available to avoid the lawsuit merely by fighting against the name change. This principle of law was recently stated in Lemyre v. Residential Energy Saving Products Inc., 2019 ONSC 7378 which says:
 This is an obvious case of misnomer. The test in Davies v. Elsby Brothers Ltd.,  3 All ER 672 was accepted by the Supreme Court of Canada in Ladouceur v. Howarth, 1973 CanLII 30 (SCC),  SCJ No. 120. It is:
How would a reasonable person receiving the [statement of claim] take it? If, in all the circumstances of the case and looking at the document as a whole, he would say to himself: “Of course it must mean me, but they have got my name wrong.” Then there is a case of mere misnomer. If, on the other hand, he would say: “I cannot tell from the document itself whether they mean me or not and I shall have to make inquiries,” then it seems to me that one is getting beyond the realm of misnomer.
 In the circumstances there is a strong case that the named defendant is the employer. There is evidence that the proposed defendant was also the employer. There is no prejudice in allowing the plaintiff to plead both.
 The proposed defendant must have known upon reading the statement of claim, “Of course it must mean me.” It operated through the same human beings as the named defendant at the same address. It hired the same lawyer to defend this action. The employer is entitled to arrange its corporate structure as it pleases but the employee is only responsible to serve notice of her complaint in such a way as to bring enough knowledge to the employer to let it defend the claim. She does not have to name the defendant with legal precision.
 For these reasons, I gave leave to the plaintiff to amend the statement of claim as asked.
Further case law on more concerning misnomer issues, such as whether the correction of a name is actually the addition of a name after expiry of a limitation period, being the time limit for starting a lawsuit, is provided in detail within the case of Tschirhart v. Grand River Hospital, 2019 ONSC 6650 wherein various references to numerous past cases were made as follows:
 The test for misnomer was set out by K.M. van Rensburg J. (as she then was) in Spirito v. Trillium Health Centre,  O.J. No. 3832 (S.C.J.); aff’d 2008 ONCA 762 (CanLII) at paragraphs 3-4:
"3 The test for determining whether an amendment is for misnomer or for the addition of a new defendant is whether the "litigating finger" is pointed at the proposed defendant in the Statement of Claim; that is, would a person having knowledge of the facts be aware of the true identity of a misnamed party by reading the Statement of Claim? If so, the defendant will be substituted unless there is prejudice that cannot be compensated for in costs or by an adjournment (Davies v. Elsby Brothers Ltd.,  3 All E.R. 672; Moreau v. Northwestern General Hospital (1988), 1988 CanLII 4810 (ON SC), 65 O.R. (2d) 128; Rakowski et al. v. Mount Sinai Hospital et al. (1987), 1987 CanLII 4113 (ON SC), 59 O.R. (2d) 349; McArthur v. Kaal,  O.J. No. 1525). The alleged expiry of a limitation period cannot be set up as "prejudice" where the initial claim against the misnamed defendants was made within the limitation period (Kitcher et al. v. Queensway General Hospital et al., 1997 CanLII 1931 (ON CA),  O.J. No. 3305).”
 Ontario courts have regularly cited the following test from Davies v. Elsby Brothers Ltd.,  3 All E.R. 672 (Eng. C.A.) at p. 676:
“The test must be: How would a reasonable person receiving the document take it? If, in all the circumstances of the case and looking at the document as a whole, he would say to himself: "Of course it must mean me, but they have got my name wrong". Then there is a case of mere misnomer. If, on the other hand, he would say: "I cannot tell from the document itself whether they mean me or not and I shall have to make inquiries", then it seems to me that one is getting beyond the realm of misnomer. One of the factors which must operate on the mind of the recipient of a document, and which operates in this case, is whether there is or is not another entity to whom the description on the writ might refer.” (Ormerod v. Strathroy Middlesex General Hospital, 2009 ONCA 697 (CanLII) at para. 11; Spirito v. Trillium Health Centre, 2008 ONCA 762 (CanLII) at para. 12; Mohabir v. Mohabir, 2014 ONSC 5484 (CanLII) at para. 13; Bertolli et al v. Toronto (City) et al, 2017 ONSC 7534 (CanLII); aff’d 2018 ONCA 601 (CanLII) at para. 19).
 In Urie v. Peterborough Regional Health Centre, 2010 ONSC 4226 (CanLII), O’Connell H.K. J. emphasized the importance of assessing the Statement of Claim to determine if there is a “litigating finger” as opposed to “a moving target”, cautioning against vagueness and non-specificity:
107 It is clear that an assessment of the statement of claim is required to analyze whether the case falls within the misnomer category. This assessment will define whether a litigating finger is in play or if the claim aims itself at a moving target. Where fictitious names are used, such as John or Jane Doe, it is the assessment of whether the proposed defendant knew that he/she was the intended defendant that becomes seminal in the analysis.
108 When dealing with allegations in a claim as stated in Spirito, vagueness and non specificity weigh heavily if not definitively against a finding that misnomer is present. General assertions are ripe for the 'moving target' argument and are contra the 'litigating finger' test. The Court is likewise entitled to refer to whether medical records would have identified the defendants by name. Delay in seeking to amend the claim by resort to misnomer must be accompanied by a reasonable explanation. All of these factors were considered by Master Abrams in Parody v. Fenwick  O.J. No. 3352.” (Urie at paras. 107-108).
 The Court of Appeal has held that the doctrine of misnomer applies notwithstanding the passage of a limitation period and that due diligence is not required:
1 On a motion to correct the name of a defendant on the basis of misnomer, as long as the true defendant would know on reading the statement of claim he was the intended defendant, a plaintiff need not establish due diligence in identifying the true defendant within the limitation period.
19 If the respondents on the motion for misnomer had raised the issue of due diligence, they would not have succeeded. The respondent Domljanovic would have known on reading the statement of claim that he was the intended defendant. The jurisprudence is clear that, in such circumstances, due diligence does not apply. In Kitcher, the name of the correct defendant was in the plaintiff’s solicitor’s file. In Lloyd, the name of the correct defendant municipality was readily ascertainable by typing in the location of the road in issue. The law that governs the addition of a party after the expiry of a limitation period does not apply.” (Stechyshyn v. Domljanovic, 2015 ONCA 889 (CanLII) at paras. 1 and 19).
The law on correcting an incorrectly named person appears relatively clear where the issue is merely whether a person named should be corrected because the name is incorrect; however, where the issue of correcting a name may actually be a backdoor effort to adding a new name or adding a new person after expiry of a limitation period, the case law becomes more complicated; however, generally, where the issue is simply that a person was named incorrectly and an amendment is sought to correct the incorrect name, the courts will allow the correction and apply the correction retroactively as if correct from the start.