A second Starbucks Corp location in Buffalo, New York, has become unionized after the federal labor board on Monday certified the results of last month's election there.
Several ballots were in dispute for the Genesee Street location, but the National Labor Relations Board (NLRB) agreed with the Workers United union that certain ballots should be tossed out, making the final vote 15-9 in favor of the union.
The global coffee chain has 10 days to challenge the NLRB's decision.
A Starbucks spokesman said the company is evaluating its options and believes the employees whose ballots were set aside should be able to vote.
"We've been clear in our belief that we are better together as partners, without a union between us at Starbucks, and that conviction has not changed," he said.
If the decision remains standing, it would mark only the second company-owned Starbucks location in the United States to form a union.