The world's largest coffee chain will also boost starting pay by 5% in order to help attract and retain employees.

The memo, dated Nov. 2, was first reported by Business Insider on Wednesday.

The increase is "one of the most substantial investments in pay in our company's history," Rossann Williams, Starbucks' president of U.S. retail, wrote in the memo.

Employees with the company for three years or more will get at least an 11% pay hike, and the company will increase the premium it already pays above minimum wage in every market, it said.

(Reporting by Hilary Russ; editing by Diane Craft and Sam Holmes)

By Hilary Russ