When does the statute of limitations commence for a legal malpractice claim?  In short, it commences on the date of the mistake.  It can be tolled by continuous representation.  In Ross v Mashkanta, LLC  2021 NY Slip Op 32873(U) December 23, 2021 Supreme Court, Kings County
Docket Number: Index No. 508310/2019 Judge: Carl J. Landicino, the limits of continuous representation were tested, and plaintiff lost.

“In relation to the related foreclosure action, the Plaintiff claims that Mascolo failed to appear on a summary judgment motion which was granted on Plaintiffs default. Summary judgment, in the related litigation, was granted on default against the Plaintiff on July 14, 2010.
The Plaintiff also claims that these failures subjected the Plaintiff to a judgment of foreclosure in relation to his property. The Plaintiff contends that Mascolo failed to appear or oppose a motion/application for judgment of foreclosure. The Plaintiff contends that, as a consequence, a judgment of foreclosure and sale was issued on June 20, 2012. The instant proceeding was commenced against Mascolo on April 12 2019, more than six years after judgment was entered in the foreclosure litigation. The Plaintiff alleges that the interval between the award of the judgment and commencement of this proceeding is irrelevant because the continuous representation doctrine applies.

The doctrine of continuous representation applies when there is “clear indicia of an ongoing, continuous, developing, and dependent relationship between the client and the attorney which often includes an attempt by the attorney to rectify an alleged act of malpractice” (Stein Industries, Inc. v. Certilman Balin Adler & Hyman, LLP, 149 AD3d 788, 789, 51 N.Y.S.3d 183, 185 [2d Dept 2017] quoting Luk Lamellen U Kupplungbau GmbH v. Lerner, 166 AD2d 505, 506- 507, 560 N.Y.S.2d 787 [2d Dept 1990]). However, the Plaintiff has repeatedly represented that his relationship with Mascolo terminated in November of 2012, when he retained new counsel to represent him in the foreclosure litigation. The Plaintiff alleged that,

…subsequent to defendant Mascolo allowing the action in foreclosure to go to default judgment and ultimately to a judgment of foreclosure and sale which was filed July 3, 2012, defendants Levy and Nau substituted in for third-party defendant Mascolo.
As a consequence of Defendant Mascolo’s failure to represent his interests, in or about November 2012, Plaintiff retained Defendants Levy and Nau, doing business as Levy and Nau PC, to represent him in the action brought against him by Mashkanta, and in that capacity, to move in that action to stay the foreclosure and sale. Plaintiff was unaware of any prior history of relationships and/or transactions among Mashkanta, Mascolo, Levy and Nau at the time he retained Levy and Nau to represent him.

(See First Amended Verified Complaint at paragraph 61-62, NYSCEF Doc. No. 12, 13 1).

Accordingly, the doctrine of continuous representation is inapplicable here. This proceeding was commenced after the statutory limitation period expired. Therefore, the ninth cause of action for malpractice is dismissed.”