Bill and Melinda Gates agreed how to divide their property and assets before announcing their divorce on Monday, according to US media.
The billionaire couple, who have been married for 27 years, reportedly signed a separation contract outlining how their estate would be split.
But they did not sign a pre-nuptial agreement before their wedding in 1994.
The couple run the Bill & Melinda Gates Foundation, which has spent billions on charitable causes around the world.
They have pledged to continue to work together at the foundation once their divorce is finalised.
Bill Gates, 65, is the fourth wealthiest person in the world, according to Forbes, and is worth $124bn (£89bn).
He made his money through the firm he co-founded in the 1970s, Microsoft, which is the world’s biggest software company.
The couple’s estate is believed to include multi-million dollar properties in Washington, Florida and Wyoming. Their main residence is a lakeside mansion in Medina, Washington that is reported to be worth at least $127m.
The couple filed for divorce at a court in Seattle on Monday, according to documents obtained by a number of US media outlets and published by the TMZ website.
“This marriage is irretrievably broken,” the petition for divorce states. “We ask the court to dissolve our marriage.”
It says the couple’s property, business interests and assets should be divided “as set forth in our separation contract”. That contract, however, has not been made public.
The pair have three adult children and spousal support is not needed, the documents state.
They have each hired three lawyers to represent them. The lawyers for Melinda, 56, include Robert Cohen who has previously worked for clients such as Ivana Trump, Michael Bloomberg and Chris Rock.
Bill, meanwhile, has hired three lawyers based in Los Angeles.
The pair announced their divorce in joint statements posted on Twitter on Monday, saying “we no longer believe we can grow together as a couple”.
“After a great deal of thought and a lot of work on our relationship, we have made the decision to end our marriage,” they said.