Research from think tank Coqual found black professionals were 81% more likely than white professionals to say their company was not fair at all or only slightly fair.
Nearly half (46%) of black workers said two years would therefore be the limit they would stay with their employer, compared to 34% of white workers.
Black employees in the workplace:
Succeeding as a black woman in business
HR needs to take accountability for black representation
Sandra Kerr, race director at Business in the Community (BITC), said companies need to promote fairness at work from board level.
Speaking to HR magazine, she said: "Employers must commit at board level to zero tolerance of harassment and bullying and make equity, diversity and inclusion the responsibility of all leaders and managers."
"The reality is that too many black, Asian, mix-raced and other ethnically diverse employees are treated unfairly in the workplace.
A quarter of ethnically diverse employees have witnessed or experienced racial harassment or bullying from managers, and this increases to nearly a third for black employees, which is unacceptable."
The research also highlighted how determined black workers are, with 63% described as very or extremely ambitious - a higher percentage than any other racial group surveyed.
This ambition was often met with obstacles; 76% said they had to work harder to advance compared to 30% of white
professionals, 42% of Asian workers, and 52% of mixed-race employees.
Julia Taylor Kennedy, Coqual’s executive vice president said: "Black professionals in the UK are experiencing harsh daily realities. “While many companies are having more conversations about race at work, they are not leading to much action– which can be incredibly dispiriting."
Coqual surveyed 1,035 people between March and April 2022: 385 black professionals, 404 white professionals, 108 Asian professionals, 107 mixed-race professionals, and 31 professionals of other racial groups.