But, he accepted some individual contributions too.
Now, heading into what is expected to be a tough general election with presumptive Democratic nominee Hillary Clinton, Trump appears to be getting serious about raising campaign cash. Since securing the nomination, Trump has begun encouraging donations, attending several organized fundraisers, and on Thursday, he held a meeting with donors in New York.
Here’s a look at some of the key members of Trump’s campaign finance apparatus:
1. Steven Mnuchin
While it is not the first time Mnuchin will work alongside Trump, the GOP candidate’s national finance chairman is tasked with bringing his “expertise” in finance to operate an “extremely successful” joint fundraising entity with the Republican National Committee.
Mnuchin, the former chairman and CEO of Dune Capital Management LP, a private investment firm, has a history of donating to both Republican and Democratic candidates. He donated repeatedly to Hillary Clinton for her Senate run and first presidential campaign -- and also holds business ties to some of Clinton’s mega donors.
2. Woody Johnson
“Woody Johnson, owner of the NYJets, is @JebBush’s finance chairman. If Woody would’ve been w/me, he would’ve been in the playoffs, at least!” Trump tweeted back in January.
But Johnson and Trump have since patched things up.
“I think they confuse his persona with the kind of person he actually is,” Johnson said. “You have to see him through his kids, in a way, and his wife.”
3. Ray Washburne
Washburne, a Dallas investor and newly-appointed vice chairman of The Trump Victory Committee fundraising partnership between the RNC and the Trump campaign, is running Trump’s finance committee.
The former RNC finance chairman, who stepped down last year to lead New Jersey Gov. Chris Christie’s finance team, recently laid out an ambitious fundraising goal.
“It’ll be $1 billion plus,” Washburne said in an interview with the Dallas Morning News, adding, “there’s only one team to be on at this point.”
4. Tom Barrack
Barrack, a real estate investor, announced his support of Trump in February and, ahead of the California primaries, held the first fundraiser for Trump at his home in the Golden State.
The Rebuilding America Now PAC also spent $1.1 million in national airtime in targeted states starting June 8 with its first ad attacking the Clintons.
5. Diane Hendricks
Hendricks, a Wisconsin businesswoman who was a top financial contributor for Wisconsin Gov. Scott Walker, has been chosen to join Washburne and four others as vice chairs of The Trump Victory Committee.
The billionaire co-founder and chairman of ABC Supply contributed $5 million to Unintimidated PAC, a super PAC created to support Walker’s failed presidential campaign.
Sheldon Adelson is a member of America’s mega-rich. The owner of the casino company, Las Vegas Sands, Forbes estimates his net worth at $26.9 billion.
A source within the Trump campaign confirmed to ABC News that Adelson, who endorsed Trump last month, will contribute a substantial amount of money to Trump's campaign. The New York Times reported that Adelson is willing to fish out $100 million or more to Trump.
In the 2012 election, he single-handedly funded Republican candidate Newt Gingrich's campaign, and once Gingrich dropped out, gave millions to GOP nominee Mitt Romney.
ABC’s Shushannah Walshe, John Santucci and Meghan Keneally contributed to this report.