Continuous representation of a client by the attorney acts as a toll of the statute of limitations.  In New York, a legal malpractice cause of action accrues at the time of the mistake, but a client is not expcted to fire the attorney and sue, so long as the attorney continues to represent the client in the same matter. While a continuing relationship of trust and confidence must exist, the most easily recognizable fact [especially in litigation] is that the lawyer continues to be the attorney of record.

Texas is apparently different, as this article by James (Sandy) McCorquodale  sets forth.

"The client’s divorce proceeding resulted in the entry of a Decree of Divorce on January 23, 1998. Subsequent to entry of the Decree of Divorce, the client was periodically represented by the lawyers on matters related to the enforcement of that decree. The underlying cause of action was filed on June 24, 2004.

Manning and the other defendants filed an Original Answer affirmatively alleging that the client’s claims were barred by limitations. The lawyers subsequently filed a traditional and no-evidence Amended Motion for Summary Judgment alleging that the client’s claims were barred by limitations and a lack of causation. The client contended that limitations did not operate to bar her cause of action for three reasons: (1) limitations was tolled during the existence of an attorney-client relationship; (2) accrual of her cause of action was deferred due to the discovery rule; and (3) limitations was tolled due to fraudulent concealment by The lawyers. The client further contended the summary judgment evidence raised a question of fact as to causation.

The trial court granted summary judgment in favor of the lawyers, holding that the client’s claims were barred both by the statute of limitations and lack of causation. The Court of Appeals affirmed.

Hughes tolling rule held inapplicable
The Court of Appeals found that the Hughes tolling rule was inapplicable:

Legal malpractice claims are governed by a two year statute of limitations. A legal malpractice claim accrues when the legal injury occurs, unless there is a legal basis for tolling limitations. Appellant’s legal malpractice claim centers upon her allegation that she received an inadequate division of community property when Manning incorrectly advised her that she was not entitled to a share of referral or contingency fees from lawsuits pending at the time of her divorce. Therefore, Appellant’s legal malpractice claim accrued when she sustained a legal injury, which would have been at the time the community property was divided by the entry of a decree of divorce.

Appellant, relying upon Willis v. Maverick, would have us adopt a bright line rule that says in a legal malpractice cause of action, limitations is tolled so long as the attorney-client relationship exists between the parties. Appellant’s reliance on Willis is misplaced. The existence of an attorney-client relationship does not, standing alone, toll limitations in a legal malpractice cause of action. Rather, limitations in a legal malpractice cause of action is tolled due to the attorney-client relationship only when the attorney’s malpractice occurs and is discoverable during the course of the underlying litigation being pursued by the attorney on behalf of the client. The Hughes rule, which tolls the limitations period until all appeals in the underlying action are exhausted, is expressly limited to cases involving claims of attorney malpractice in the prosecution or defense of the underlying litigation and does not apply to malpractice claims involving transactional work.

Appellant’s Decree of Divorce was signed on January 23, 1998. Therefore, applying the Hughes rule to the facts of this case, the statute of limitations on Appellant’s legal malpractice cause of action was tolled until February 22, 1998, the date her divorce decree became final.

Subsequent to the Decree of Divorce becoming final, Manning performed legal services for Appellant in the nature of work incident to the enforcement of the decree. Appellant would have this Court extend the Hughes rule to revive the tolling of limitations during these periods of representation. We conclude that reasons underlying the Hughes rule are inapposite to the facts of this case, and we decline to extend that rule without clear precedent. "