“The law with respect to misnomer is well-settled.
Rule 5.04(2) [of the Rules of Civil Procedure] provides the court with discretionary jurisdiction to correct a misnomer. The entitlement to misnomer relief is conditional on satisfying the “litigation finger test”. In Stechyshyn v. Domljanovic 2015 ONCA 889 at para. 1, the Court of Appeal described the test as follows:
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.
With respect to misnamed plaintiffs, misnomer relief is available where a party intended to commence proceedings in one name “but, in error, the proceedings were commenced in another name”; see Mazzuca v. Silvercreek Pharmacy Ltd., 2001 CanLII 8620 at para. 48 (Ont. C.A.); and Picov and Picov Farms Ltd. v. Generac Power Systems Inc. et al., 2020 ONSC 852.
Rule 5.06(2) provides the court with a residual discretion to refuse misnomer relief even when the litigation finger test is satisfied. In exercising this jurisdiction, the factors that deserve the greatest weight include whether the correct party was misled or was unduly prejudiced; however, where the mistake is more than a mere irregularity, the court may exercise its residual discretion to refuse to allow the correction; see Ormerod v. Ferner, 2009 ONCA 697 at paras. 28-32.”