If your employer quietly slips a mandatory arbitration policy into your inbox and you never read it, can that really waive your right to sue? According to the Ninth Circuit, no.
In a recent appeal involving Thermo Fisher Scientific and one of its employees, the court held that unread emails and continued employment alone aren’t enough to show an employee agreed to arbitrate. Silence in a crowded inbox doesn’t equal consent.
How the Dispute Arose
Rickes sued Thermo Fisher in California state court for age discrimination and related state-law claims. After Thermo Fisher removed the case to federal court, it moved to compel arbitration under a Mutual Dispute Resolution Agreement (MDRA) the company had introduced in 2019 by email with a 45‑day opt‑out window.
Thermo Fisher could show it sent Rickes four MDRA-related emails, but its own records did not show that he opened them, clicked the agreement link, or otherwise interacted with the materials. Rickes said he did not recall any MDRA communications and had never seen the agreement before this lawsuit.
Nonetheless, Thermo Fisher argued that his continued employment and failure to opt out meant he accepted arbitration. The district court denied the motion to compel, and Thermo Fisher appealed to the Ninth Circuit.
No Proof of Agreement
The Ninth Circuit boiled the issue down to basic contract law: had the parties actually formed an agreement to arbitrate under California law?
Contract formation requires notice and mutual assent, meaning the employee knew about the terms and, through words or conduct, objectively agreed to them. Silence alone does not qualify.
Here, everyone agreed California law applied and that Thermo Fisher, as the party seeking to enforce arbitration, had the burden to prove an agreement existed. The company showed it sent four MDRA emails to Rickes, but there was no evidence he opened them, clicked the link, or otherwise interacted with the agreement, and Rickes said he did not recall any MDRA communications at all. In the electronic context, the court explained, assent usually appears as some affirmative action: clicking, checking a box, or otherwise engaging with the terms.
Thermo Fisher argued that Rickes accepted the MDRA by staying employed and not opting out within 45 days. But the Ninth Circuit rejected that theory, holding that continued employment without proof of actual notice is not enough to establish mutual assent to new arbitration terms.
No Proof of Consent
Thermo Fisher pointed to prior cases where courts enforced arbitration programs and urged the Ninth Circuit to do the same. But those decisions all involved objective evidence of assent: signed acknowledgments, undisputed proof that employees received and reviewed the terms, or clear notice that arbitration was a condition of employment.
Here, Thermo Fisher could not show that Rickes ever opened the MDRA emails, accessed the agreement, or signed anything. With no outward manifestation of consent, the company failed to meet its burden of proving that an arbitration contract existed, so the Ninth Circuit affirmed the denial of its motion to compel.
In other words, Thermo Fisher doesn’t get the streamlined, private forum it was counting on. Because it couldn’t prove that Rickes ever agreed to the MDRA, his age discrimination claims remain in court.
Takeaways for Workers and Employers
While the Ninth Circuit’s decision is an unpublished memorandum and not precedential under the court’s rules, it offers clear practical lessons.
For employees, the ruling confirms that your inbox is not a contract by default. Under California law, an employer cannot bind you to arbitration merely by emailing terms you never read and treating your silence as agreement. Courts look for some affirmative act – e.g., clicking “I agree,” signing an acknowledgment, or otherwise engaging with the terms. In Thermo Fisher’s case, the company’s own records showing no interaction with its emails undercut its position. That doesn’t mean workers can safely ignore every arbitration email; if an employer can show you opened, reviewed, or signed off on terms, arbitration may still be enforced. But the decision underscores that courts are reluctant to infer consent from pure inaction, especially when legalese is buried in routine work email.
For employers, the case is a warning that “send and forget” rollouts are risky. If you want an electronic arbitration program to stick, you need mechanisms that reliably capture affirmative consent (e‑signatures, required click‑throughs, or documented onboarding where terms are actually presented and accepted). An opt‑out window paired with continued employment will not carry the day if you can’t first prove that employees had real notice and a chance to review the agreement. Judges will look closely at what your records show: did the employee open the message, access a portal, or sign anything? Without that evidence, a motion to compel arbitration may fail.
More broadly, the case highlights a tension in the modern workplace: employers increasingly rely on email and online portals to deliver important legal terms, while employees are inundated with digital communications. Applied here, California contract law insists on two basic themes: notice must be real (not hypothetical), and silence is not consent.
As companies continue to roll out major policy changes by email and electronic handbooks, this decision serves as a reminder that an unread message in a crowded inbox is not enough to rewrite employees’ rights.
