Starbucks says an employee in Philadelphia has been fired after allegedly mocking a customer with a stutter.

The coffee chain says the behaviour did not reflect the experience customers should have and the employee is no longer with Starbucks.

A person on Facebook posted that his friend stuttered when giving his name, and that the barista made light of it verbally and then spelled the name with extra letters.

Tan Lekwijit, a student from Philadelphia, wrote: "The barista said, 'Okay, S-s-s-sam.'

"When he received his coffee, he was shocked to see that his name on the cup was written as 'SSSAM', which was disrespectful."