Bill Gates and his wife Melinda did not sign a prenuptial agreement when they married in 1994, court documents reveal.
Bill, 65, and Melinda, 56, announced their divorce after 27 years of marriage via Twitter on Monday.
Documents obtained by Daily Mail show Melinda was the one to file for divorce, and claimed the marriage was "irretrievably broken".
It also showed the couple had a separation agreement, but not a prenup - and with Bill's fortune estimated over US$130 billion, it may make the divorce very difficult.
The pair own a private jet and a number of properties including a mansion in Lake Washington and houses in five states.
Their Washington home took seven years to build and is now worth an estimated US$125 million. The property has seven rooms, an indoor-outdoor pool with an underwater music system, and an art-deco cinema.
Bill is also an avid luxury-car collector, according to Business Insider, and owns a Porsche 939 Turbo, a Jaguar XJ6, a Ferrari 348, a Porsche Taycan, as well as a rare Porsche 959.
The couple announced their divorce on Monday, sharing a joint statement on Twitter.
"After a great deal of thought and a lot of work on our relationship, we have made the decision to end our marriage," they both wrote on social media.
"Over the last 27 years we have raised three incredible children and built a foundation that works all over the world to enable all people to lead healthy, productive lives."
Their statement continued: "We ask for space and privacy for our family as we begin to navigate this new life".