Dia Dipasupil/FilmMagic Tom Brady and Gisele Bündchen
Sources told PEOPLE that they will both file in Florida on Friday morning.
"The settlement is all worked out," a source with knowledge of the situation tells PEOPLE. "They've been working on the terms this whole time."
The source added: "They agreed to joint custody of the kids."
The decision to find a lawyer has left Brady "trying to figure out what to do," a source tells PEOPLE, and he is now looking for one himself. Representatives for Bündchen and Brady did not respond to PEOPLE's request for comment.
Now, with a possible divorce on the horizon, the couple — who share son Benjamin Rein, 12, and Vivian, 9, along with Brady's 15-year-old son John Edward, whom he shares with ex Bridget Moynahan — may likely squabble over the division of their multimillion-dollar assets, divorce attorney Sue Moss with Chemtob Moss Forman & Beyda LLP, who is not connected to the couple, tells PEOPLE.
"The big challenge for him is everything will be determined at the height of his income, because to get him to come back, the Tampa Bay Buccaneers had to come up with a lot of cash — and that is the baseline for determining the support in this case," Moss says.
"At the beginning, Gisele was earning more than him, and he kept on winning and his income got more and more substantial and it outgrew hers," Moss continues. "And because of the timing, the case will be determined based upon the height of earnings."
According to NYC divorce attorney Jacqueline Newman of Berkman Bottger Newman & Schein LLP, who is not connected to Brady or Bündchen, a prenuptial agreement is likely already involved, given the powerhouse couple's massive net worth.
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"People of this magnitude of wealth don't generally get married without a document that's going to dictate what's going to happen if it doesn't run its course," Newman tells PEOPLE.
"My guess is that a lot of this is already worked out. So, there's probably a prenuptial agreement that's going to dictate a lot of this, but if there are some properties that were purchased while they were married — marital residences — there may be fights about that," says Newman.
"There probably were assets that were acquired during the marriage, so there may be squabbles about that to say the least," says Newman. "That said, I think they are going to settle this, assuming they go forward with it — outside of the press."
Brady and Bündchen currently own at least four properties: a house at the exclusive Yellowstone Resort in Montana, a $3.5 million NYC apartment, a home in Costa Rica and the $17 million mansion they purchased in Miami's elite Indian Creek Island.
But Newman points out the main point of contention may likely be over custody of their children.
"It really does seem that [Bündchen] has dedicated her life to these children," says Newman. "I'm sure he is dedicated to the children, but he travels a lot. He's not involved as much in the day to day. She may want more stability for them."
Newman says that they would hopefully work out an arrangement for the children ahead of time if they go through with a divorce, "because the worst thing they could do is pull their kids through a custody battle."