“Thought it was done, but I guess it’s never really over.”

When international pop superstar Katy Perry sang these lyrics five years ago, she may have been predicting her long-running trade mark battle with an Australian fashion designer.

Katie Jane Taylor sued Perry in October 2019, more than 10 years after the performer behind hits like Firework, Roar and Dark Horse started selling merchandise, including clothing, under her own name.

The designer had sold her own line of clothing under the Katie Perry label since 2007 after becoming inspired by a trip to Italy.

She achieved a further legal win in the case today with the High Court allowing her lawsuit against Perry to continue by granting her application for special leave.

This will allow her to try overturn a full Federal Court judgment from November that the US singer, whose real name is Katheryn Hudson, did not infringe the Katie Perry mark by selling clothing during the 2014 Prism tour in Australia.

Three judges from the Full Court had thrown out Justice Brigitte Markovic’s 2023 findings that Perry’s firm Kitty Purry had infringed the mark.

Taylor’s own trade mark would be deregistered, the judges said.

Today, her barrister Christian Dimitriadis SC said the appeal judges had erred in their interpretation of Australian trade mark law.

Just because Perry had a reputation as a pop star at the time the Katie Perry trade mark was registered in 2009 did not mean she also had a reputation for selling clothing at the time, he argued.

The Full Court found that while the singer was not known for selling clothes in 2009, her status as a celebrity meant she was likely to expand into selling at least branded clothing later.

There was a chance this could cause deception or confusion amongst those buying items from the fashion designer thinking they were related to the pop star, the Full Court said.

High Court Justice Jayne Jagot questioned this on Friday.

“If you’re sufficiently famous, the capacity is to monetise in all kinds of directions, not just clothing,” she said.

The logic the celebrities could use their reputation to expand into clothing could also apply and impact Australians selling products ranging from whiskey and wine to perfume and invisible teeth braces, the judge said.

Taylor had the misfortune of choosing a trade mark similar to someone who became famous and then proceeded to sell clothing in Australia knowing she was infringing that mark, Mr Dimitriadis said.

The Full Court’s decision to deregister the Katie Perry brand because it found the designer applied for the trade mark knowing of the US singer’s reputation was incorrect, he submitted.

Perry’s barrister Matthew Darke SC unsuccessfully argued that the High Court should not hear the case as it did not involve an important question of law.

Taylor declined to comment on the case after the hearing.

The High Court will hear the full appeal at a later date.