In a huge win for employers regarding worker compensation, the U.S. Supreme Court ruled that companies are not required to pay employees for any time they spend going through security checks at the end of their shifts. The case focused on an Amazon.com Inc warehousing contractor.

Cannot Claim Worker Compensation

In a unanimous 9-0 vote the court decided that employees of Integrity Staffing Solutions facilities in Nevada (a shipment and processing plant for Amazon merchandise), cannot claim any worker compensation for the time they spend undergoing security screening. Justice Clarence Thomas wrote that since the screening process is not a “principal activity” of the workers’ jobs it is not subject to worker compensation.

According to workers, that time can be up to half an hour a day. Amazon spokeswoman, Kelly Cheeseman, said the claims of the screening time taking that long were “simply not true,” adding that Amazon’s screening process was designed to take only 90 seconds per employee at each of its facilities. An attorney for the plaintiffs, Mark Thierman, said the ruling will leave thousands of workers “short-changed a half hour per day.” Workers will still be able to pursue their claims under state law.

Other Companies, Similar Disputes

The ruling is likely to benefit other similar disputes at other companies including Amazon, CVS Health Corp and Apple Inc. According to the court filings, the cases against Amazon, Integrity, and other staffing companies impact up to 400,000 workers. Plaintiffs claimed hundreds of millions of dollars in damages.

Reversal of Previous Ruling

This was the reversal of an April 2013 ruling by the 9th U.S. Circuit Court of Appeals. That decision ruled that screenings were an integral part of the job, done for the benefit of the employer, and should thus be compensated. Employees sued Integrity Staffing Solutions for both back wages and overtime pay, alleging they should have received worker compensation for all the time spent during the mandatory security screenings.

According to business group, Retail Litigation Center, the shipment and processing industry loses roughly $16 billion annually in thefts.