In estate litigation and beyond, it’s not unusual for a single lawyer to be retained jointly by multiple individuals who share a common interest. Siblings challenging a will. Co-beneficiaries disputing the actions of a trustee. Family members asserting claims under the Succession Law Reform Act[1]. Sometimes, for reasons of cost, coordination, or convenience, only one of those clients signs their name to the court documents. But when things go wrong — when a pleading backfires, a clause is triggered, or a claim is dismissed — can those who never signed the document be bound by its consequences?

This question is especially pressing in the context of no-contest clauses. These are provisions in wills that attempt to disinherit or penalize anyone who challenges the validity or terms of the will. A beneficiary who files a Notice of Objection risks forfeiting their share of the estate. But what if several beneficiaries jointly retain a lawyer, and only one of them signs the Notice? What happens to the others?

It’s a murky and under-litigated area, and one that deserves closer attention, particularly as collaborative representation becomes more common in estate disputes and as the courts wrestle with the enforceability of no-contest provisions.

The Legal Framework: Representation and Agency

At the heart of this issue is the law of agency and retainer. A lawyer who is jointly retained owes duties to all of their clients, even if only one name appears on the retainer letter or in court documents. If a pleading is filed on behalf of a client, and that client has given instructions in consultation with the lawyer, then it is typically that client who is bound by the consequences of the pleading.

But the law is less clear about whether co-clients, who may have participated in meetings, given input, or even shared in costs, are bound by the legal consequences of actions they did not formally authorize or sign.

In the estate context, that question becomes particularly thorny where the action taken — such as filing a Notice of Objection — may trigger a no-contest clause that threatens a beneficiary’s entire entitlement.

For the Argument: Shared Retainer, Shared Responsibility

Those on the “yes” side of the argument may rely on the joint retainer provisions in the Rules of Professional Conduct and on general principles of agency law. Under Rule 3.4-5 of the Law Society of Ontario’s Rules^[2], a lawyer who acts in a joint retainer must advise all clients of the implications of such an arrangement, including that there is no confidentiality as between them and that a conflict of interest may arise requiring the lawyer to withdraw.  As stated in Rule 2.04(6) of the Rules of Professional Conduct (Law Society of Ontario):

“Before a lawyer acts in a matter or transaction for more than one client, the lawyer shall advise each of the clients that:
(a) the lawyer has been asked to act for both or all of them;
(b) no information received in connection with the matter from one client can be treated as confidential so far as any of the others are concerned; and
(c) if a conflict develops that cannot be resolved, the lawyer cannot continue to act for both or all of them and may have to withdraw completely.”^[3]

When a lawyer represents multiple clients with a common interest, those clients may be considered principals of the same agent, namely, the lawyer, and thus may be jointly bound by the actions taken on their collective behalf, even if one client did not personally instruct or sign the impugned document. Courts assessing whether a non-signing client is bound may look at the broader context, including whether that client contributed to legal fees, attended joint strategy discussions, or otherwise endorsed the steps taken, directly or indirectly, by the group.

In short, the argument would go, beneficiaries cannot have it both ways: they cannot enjoy the benefits of shared representation while disclaiming the risks once things go south.

Against the Argument: No Signature, No Risk?

On the other side of the ledger is the argument that legal liability and consequences must arise from clear, affirmative acts rather than from mere association. A Notice of Objection is not merely an administrative filing. It is a formal pleading under Rule 75.03 of the Ontario Rules of Civil Procedure. Once filed, it transforms an otherwise uncontested probate application into a contentious proceeding, often triggering adversarial litigation and delaying the issuance of a Certificate of Appointment. If a beneficiary’s name does not appear on it—if they did not sign it, file it, or directly instruct it—then it may be unjust to conclude that they “objected” within the meaning of the no-contest clause. Courts generally construe such clauses strictly and are reluctant to apply them broadly or punitively.

For example, in Budai v. Milton, 2014 ONSC 5530^[4] the court struck down a clause as in terrorem, stating that it was void because it lacked a gift-over and appeared to be nothing more than an idle threat. The decision reaffirmed that forfeiture clauses must be narrow, must include substitute beneficiaries, and must not be used as blunt instruments to strip rights absent clear intent. The court emphasized that such clauses must be interpreted strictly and reasonably in favour of preserving entitlements.

In the landmark case of Mawhinney v. Scobie, 2019 ABCA 76^[5], the Alberta Court of Appeal upheld a properly drafted no-contest clause but emphasized that such clauses are designed to discourage, not prohibit, litigation. The court interpreted the clause carefully, refusing to extend it to judicial procedures permitted under statute unless explicitly excluded by the clause. The clause triggered only where the beneficiary clearly launched a challenge outside the enumerated exceptions. The Court expressly refused to give the provision a broad or punitive application beyond its precise wording.

Unless a person has personally taken steps to challenge the will, courts may hesitate to find that they have forfeited their entitlement, particularly where the clause lacks clarity. The fact that a beneficiary was part of a joint retainer may not, on its own, suffice to trigger the clause. Even if that person attended meetings or contributed to legal fees, absent clear evidence that they authorized or endorsed the objection, it may be a legal overreach to hold them accountable for its consequences.

By this argument, the effect of a no-contest clause should be limited to those who have actively and individually participated in the objection.

Canadian Case Law: A Gap in Precedent

Notably, there is no reported Canadian case — from Ontario or any other province — that directly resolves this issue. No court has yet held that a non-signing co-beneficiary who jointly retained a lawyer is automatically bound by a pleading filed by a fellow client in the context of a no-contest clause.

However, broader Canadian legal principles offer clues. In R. v. Neil, [2002] 3 S.C.R. 631, 2002 SCC 70^[6] and Canadian National Railway Co. v. McKercher LLP, 2013 SCC 39, [2013] 2 S.C.R. 649^[7], the Supreme Court of Canada reinforced that lawyers owe duties of loyalty and diligence to all clients in a joint retainer. These cases emphasize the importance of informed consent, confidentiality, and client protection — all of which play into how courts may analyze whether a co-client is bound by a contested pleading.

And while decisions like Mawhinney v. Scobie (ABCA 2019) confirm that well-drafted no-contest clauses can be enforceable even outside traditional probate challenges, they do not answer the narrower question of whether non-signing participants in a joint legal strategy can be caught by the clause.

American Insight: Conduct Over Signature

In contrast, U.S. courts have begun to address adjacent issues. In Key v. Tyler, 2024 Cal. App. LEXIS [Docket B322246]^[8],  the California Court of Appeal reversed a probate court decision and held that a beneficiary who did not initiate litigation but actively defended a disputed trust amendment could be found to have violated a broad no-contest clause. The Court emphasized that even defensive or responsive conduct may constitute a “direct contest” where the clause is broadly drafted and the conduct is sufficiently adversarial. The case was remanded to determine whether the beneficiary had probable cause for her actions, as required by California Probate Code § 21311(a)(1).

In Colorado, in the case of In re Estate of Peppler, 971 P.2d 694 (Colo. App. 1998)
Colorado Court of Appeals, Case No. 97CA1873^[9], the Colorado Court of Appeals held that a no-contest clause encompassing both direct and indirect challenges could apply to a beneficiary who substituted herself into a probate proceeding originally initiated by her daughter. The court recognized that such indirect conduct could fall within the scope of a forfeiture clause, even absent a formal objection by the beneficiary herself. However, the matter was remanded to determine whether the beneficiary had acted with probable cause, which, if established, would render the clause unenforceable under Colorado law.

However, in Sandstead-Corona v. Sandstead, 2018 CO 26^[10], the Colorado Supreme Court held that a no-contest clause could not be enforced against a beneficiary who challenged the testator’s will, where the clause applied only to contests of the trust. The Court reversed the lower court’s attempt to expand the clause’s reach and emphasized that such clauses must be interpreted strictly according to their plain language.

Texas courts strictly construe in terrorem clauses and generally avoid forfeiture unless the beneficiary’s actions fall squarely within the express terms of the clause. However, they have upheld disinheritance where a beneficiary’s conduct—such as pursuing litigation contrary to the testator’s intentions—clearly triggers the clause, even in the absence of a formal will contest^[11].

Together, these cases show that in some jurisdictions, a beneficiary’s conduct, litigation participation, or posturing in opposition to the testator’s intent — even absent a formal signature on a contest — may be enough to trigger a no-contest clause.

Loyal to Whom? Navigating Conflicts in Joint Beneficiary Representation

This scenario also raises serious questions about professional ethics and potential conflicts of interest. Where a lawyer represents multiple beneficiaries, but only one of them signs a Notice of Objection that triggers a no-contest clause, the lawyer may be in a conflict of interest, particularly if the objecting beneficiary’s forfeited share is redistributed to the remaining, non-signing clients. In such a case, the lawyer is effectively advancing a legal position on behalf of one client that may financially benefits the others, potentially without fully informed, independent consent. Rule 3.4-1 of the Law Society of Ontario’s Rules of Professional Conduct^[12]prohibits a lawyer from acting where there is a substantial risk that their duties to one client will be materially and adversely affected by their duties to another. Even if the objection was launched in good faith, the mere possibility that the lawyer’s other clients might gain from one client’s disinheritance calls for a close examination of the retainer, disclosure practices, and whether the objecting party had a realistic opportunity to seek independent legal advice.

The Practical Reality: Risk Management in Joint Representation

This dilemma raises real-world problems for lawyers and mediators alike. How should counsel manage joint retainers when only one name is going on a pleading with high-stakes consequences? Should lawyers insist on all clients signing or formally waiving participation? Should there be separate counsel retained to limit the ripple effects of risk?

From a risk management perspective, the safest course is to treat joint retainers as if everyone’s name is on the line, because it may be, even if only in argument. Clarity of documentation, separation of instructions, and express consents or waivers are all critical.

Mediators should be alert to these issues too. In caucus, when assessing risk and exposure, it is essential to know who the lawyer actually represents and what actions have been taken in the name of each client. A single document may have consequences that extend further than anyone anticipates — or intends.

A Final Word: Participation Has Consequences

The jurisprudence on no-contest clauses is shifting, not only in terms of what actions may trigger them, but who may be caught in their reach. Courts, particularly in the United States, are increasingly willing to look beyond formal filings and focus instead on conduct, participation, and strategic alignment. The cases from California, Colorado, and Texas show a consistent trend: where a beneficiary engages — directly or indirectly — in litigation that undermines the testator’s intent, they may forfeit their bequest even without ever signing a pleading.

For Canadian lawyers and mediators, this should prompt caution. While no Canadian case has yet imposed such a consequence on a non-signing co-client, the principles of agency, loyalty, and joint retainer ethics suggest it’s only a matter of time before our courts are called to weigh in. In cross-border estates, or where persuasive American precedent applies, the risks are immediate.

The takeaway is clear: shared legal strategy may lead to shared legal exposure. A retainer shared among siblings or co-beneficiaries must be carefully structured. Without clear boundaries, consent protocols, and individualized advice, one party’s objection could unintentionally jeopardize another’s entitlement, and place the lawyer squarely in conflict.

Mediators, too, must be vigilant. Representation questions should be clarified at the outset. A single objection, objection response, or affidavit, even if signed by only one client, may ripple across the case in unintended ways.

In short, the evolving law of no-contest clauses warns us that in estate disputes, silence is not always safe, and signatures are not the only sign of intent. Participation, strategy, and legal alignment matter. The consequences may reach further than anyone expects.