The former Look North presenter lost her appeal in relation to the tax years 2006/07 to 2012/13, while she was working at the public broadcaster through her personal service company Christa Ackroyd Media (CAM).
But HMRC argued she owed £419,151 in income tax and National Insurance Contributions (NICs) during that time because she claimed to be self-employed when she was not.
Ackroyd accepted during the court hearing that the BBC ultimately had the right to specify what services CAM would provide, and her contract restricted her from providing services to other organisations without the consent of the BBC. Acroyd was also obliged to perform services and BBC was obliged to pay fees to CAM on a monthly basis.
The presenter lost her 12-year job at the BBC and while the broadcaster said at the time her departure was due to “editorial reasons”, there was speculation that it was due to her freelance status dispute with the Revenue.
An HMRC spokesperson declined to comment on this individual case, but said, "Employment status is never a matter of choice; it is always dictated by the facts and when the wrong tax is being paid we put things right."
Dave Chaplin, CEO and founder of ContractorCalculator, an online portal for freelancers and contractors, said, “I have a lot of sympathy for Christa Ackroyd because the BBC encouraged her to work this way and her advisors were clearly out of their depth on IR35.
“Unfortunately for Ackroyd, whilst the case looks clear cut, it appears the tribunal made a decision based on facts cherry picked by HMRC, and HMRC has effectively put her out of a job; HMRC did not even speak to her before making its judgement and reached its conclusion on inadequate information.
HMRC has been examining a large number of freelance staff at the BBC who were paid through personal service companies.
In a witness statement, Jennifer Henderson, head of global mobility and employment tax at the BBC, revealed that HMRC began investigating 23 BBC presenters in May 2015 to establish whether they had violated IR35 rules which regulate self-employment status.
Late last year, BBC wrote to its highest-paid staff telling them they would start being taxed as BBC employees, not self-employed.
This means they are now taxed at the 45% PAYE rate, instead of the 20% corporate tax rate. Many well-known BBC personalities earning more than £150,000 previously used personal service companies, a report from the Daily Mirror said.
ContractorCalculator has warned that the public sector has seen a raft of contractors leave due to IR35 reforms, with 76% of departments losing their top talent.
The IR35 legislation, in force since 2000 to counter tax evasion by contractors, saw changes introduced in April 2017.