Billie Eilish and her brother/collaborator Finneas have left their managers of a decade, Danny Rukasin and Brandon Goodman’s Best Friends Music Management, for Jason Owen’s Sandbox Entertainment, which reps Kacey Musgraves and Kelsea Ballerini, Eilish’s rep confirms to Variety.

While the move comes as a surprise given the peaks of commercial and critical success the two have reached with the close-knit team that has been with them since the start — also including Darkroom and Interscope Records and longtime publicist Alexandra Baker, not to mention the siblings’ parents, who have played a huge role in their careers — rumors began circulating last year that the pair would be leaving Best Friends. Eilish herself has won nine Grammy Awards and 32 nominations, and two best song Academy Awards, with Finneas sharing in most of those and winning the producer of the year Grammy himself in 2020, as well as pursuing an active solo career.

The Best Friends roster includes fast-rising Interscope singer-songwriter Role Model and British vocalist Mimi Webb. The news was first reported by The Hollywood Reporter and Hits.

According to the RIAA, Eilish has racked up a remarkable 42 platinum and gold albums, singles and EPs in the U.S. alone since her breakthrough album, 2019’s “When We All Fall Asleep, Where Do We Go?” She first rose to attention when Finneas posted their song “Ocean Eyes” on SoundCloud in November of 2015, when Eilish was just 13 years old. But their team soon formed and a gradual rise ensued: She released her debut EP, “Don’t Smile at Me,” in 2017 and followed with “When We All Fall Asleep,” which led to a sweep of the four main Grammy categories the following year: album, song and record of the year and best new artist, and she was named Variety‘s Hitmaker of the Year for 2019 as well. The pair have enjoyed multiplatinum success with their two following albums, 2021’s sarcastically titled “Happier Than Ever” and last year’s “Hit Me Hard and Soft” (which spawned the hit single “Birds of a Feather”), but just as notable have been their two Oscar song of the year trophies, for the James Bond theme “No Time to Die” and the song from a pivotal scene in “Barbie,” “What Was I Made For?”

While Owen is widely known as a top country manager, with Musgraves, Ballerini, Faith Hill, Little Big Town, Kate Hudson and others on his roster, he actually begin his career at New Line Cinema, Fine Line and Spelling Entertainment before he was tapped to take over the publicity department of Universal Music’s Mercury Nashville label. He also worked some artists for the company’s Lost Highway label, which included Johnny Cash and the then-newly signed Musgraves. “I used to sit in that chair at Universal and would have to deal with the worst managers,” Owen told Variety in 2019. “And I was, like, ‘I can do better than that with my eyes closed.’ And that’s what started me thinking [about management].”

Since then, he has never looked back, as Sandbox has moved from strength to strength, recruiting highly respected Nashville veteran Jake Basden as president in January of 2023.  And with Eilish and Finneas in the fold, the company has clearly is casting its eyes far beyond country.