HMRC claims that she owes £124,000 in income tax and National Insurance contributions.
Ms Adams, 60, says she was self-employed and so the rules did not apply to her while hosting The Kaye Adams Programme on BBC Radio Scotland from 2013 to 2019.
An Upper Tribunal judge agreed in 2021, but HMRC appealed.
BBC business director Alison Denvir yesterday said its news contracts limited outside work.
But she said Ms Adams wasn’t treated as a news presenter and her “external activities” on ITV’s Loose Women would help “bring a profile to the programme”.
She said: “I accepted Kaye wasn’t caught by the guidelines.”
She said the BBC had designed ‘On Air Talent Statutory contracts’ or ‘OATS’ contracts for news presenters and journalists which moved them from being treated as freelancers to having more work benefits.
She added: “They were devised exclusively for news presenters and journalists, because the BBC editorial guidelines heavily restricted the activities of news journalists.
“For those in news there was more control on their external activities.”
The case continues.