Alexandra Wilson, a mixed-race barrister who specializes in criminal and family cases, posted a Twitter thread Wednesday detailing the experience, which she said had left her "absolutely exhausted."
In the first example, Wilson described how a security officer had assumed she must be a defendant rather than a barrister.
A fellow lawyer and a court clerk separately assumed that she was being represented in court, rather than appearing as a barrister.
She was also mistaken for a journalist, she said.
The first time, Wilson said, she "tried to shrug it off as an innocent mistake," but the repeated assumptions later led her to tweet her thoughts on the situation.
"I don't expect to have to constantly justify my existence at work," tweeted Wilson, whose book "In Black and White" is billed as a "story of race and class in a broken justice system."
Wilson did not specify where the alleged incidents took place.