The Ninth Circuit Affirms Denial Of Motion To Compel Arbitration Where Four Email Messages Containing Arbitration Agreement Sent To Employee Went Unopened

Duane Morris Takeaways: On August 5, 2026, a panel of the U.S. Court of Appeals for the Ninth Circuit affirmed a decision denying a motion to compel arbitration brought by an employee on a representative basis under California law against his employer. In Rickes v. Thermo Fisher Scientific, Inc., et al., No. 25-5138 (9th Cir. Aug. 5, 2026), the Ninth Circuit decided that a district court had properly determined that there was insufficient evidence that the plaintiff assented to the arbitration agreement that had been sent to his work email address by his employer four times. The panel decided the evidence showed the plaintiff never opened the emails, supporting his declaration that he was not aware of those emails and never saw them until after he filed suit. The Ninth Circuit then held that the district court correctly decided that the plaintiff’s continued employment after he received the emails could not be construed as consent to arbitrate workplace claims because silence does not constitute assent. 

Employers with a workforce in California who are considering rolling out or updating arbitration programs should take note and consider designing and implementing appropriate non-coercive, non-electronic methods of following up with employees who do not open or respond to such emails.

Case Background

Plaintiff Scott Rickes brought a lawsuit in the U.S. District Court for the Southern District of California against his employer, Thermo Fisher Scientific, Inc. (“Thermo Fisher”), alleging he and others similarly situated whom he seeks to represent were unlawfully subjected to age discrimination under California law. Thermo Fisher moved to compel arbitration, relying on emails the company sent to the plaintiff’s work email address that contained a link to an agreement to arbitrate claims such as this. Thermo Fisher relied on evidence it submitted to the district court to demonstrate that it sent that email to the plaintiff four times in 2019. The plaintiff, however, declared that he never saw those emails because he was very busy at work and it was not uncommon for him to have unopened emails. Id. He argued that there was insufficient evidence to demonstrate that he assented to the arbitration agreement and therefore it could not be enforced.

The district court denied Thermo Fisher’s motion to compel arbitration, finding no evidence that an agreement to arbitrate had been reached by the parties under California contract formation principles. Thermo Fisher appealed the district court’s ruling.

The Ninth Circuit’s Decision

On August 5, 2026, a panel of the Ninth Circuit, in an unpublished decision, unanimously affirmed the district court’s decision. The Ninth Circuit agreed no evidence had been submitted to demonstrate that the plaintiff had ever opened any of the emails containing a link to the arbitration agreement. Asa result, there was no evidence that the plaintiff saw the arbitration agreement.

In explaining its rationale, the Ninth Circuit first noted that a contract can only be formed with mutual assent. Under California law, this requires both notice of an agreement and mutual assent to it. Mutual assent is absent when a party has not received notice of the proposed contract. 

The Ninth Circuit also concluded that while “outward manifestations” of assent can be objectively inferred by a party’s conduct at times, such is not the case where this plaintiff’s conduct was mere silence in response to the offer to form an agreement to arbitrate claims related to his employment. Id. at 3. 

As a result, the Ninth Circuit considered – and rejected – Fisher Scientific’s argument that where a current employee continues to work at his position after having been informed that an arbitration agreement will govern any employment claims going forward, such employee is legally considered to have assented to arbitration by inference. Due to his silence, the Ninth Circuit decided the plaintiff could not have been deemed to have accepted the agreement by failing to opt out within forty-five days. 

Finally, the Ninth Circuit dispensed with Fisher Scientific’s argument that continued employment despite unsigned arbitration agreements can constitute assent to arbitration because the cases cited were inapposite. Some applied to situations where a plaintiff was subject to an employment agreement that he agreed to that contained an arbitration clause (which is not the case in this matter) and others applied to cases where an employee signed a receipt saying they received an agreement or an employee handbook containing an arbitration provision (again not at issue in this matter). 

Implications For Employers

Employers with a workforce in California should heed this ruling if they are planning on rolling out new or revised arbitration agreements to cover potential employment law claims. Relying solely upon electronic means to implement such a workplace arbitration program is likely insufficient to bind employees. Employers should consider planning for non-electronic follow-up contact methods to reach employees who do not respond to emailed requests to consent to arbitration agreements; implementing tracking methods to identify such employees; and carefully crafting such follow-up communications to neutrally and in a non-coercive manner inform the employees of the need to open the email and respond to it in a timely manner. Doing so could mean the difference between facing expensive and protracted litigation in California state or federal court involving potential additional aggrieved individuals and perhaps defending a single plaintiff arbitration matter at much lower costs.