Donald J. Trump Is Racing Against Time to Find a Half-Billion Dollar Bond

Donald J. Trump is on the clock.

The $454 million judgment that a New York judge imposed on Mr. Trump in his civil fraud case took effect on Friday, placing the former president in a precarious position.

Now, he must either come up with the money quickly or persuade a company to post a bond on his behalf, essentially vouching for him to the court with an I.O.U.

The bond is likely to be his best bet: Mr. Trump, who also faces an $83.3 million judgment in an unrelated defamation case, does not have enough cash on hand to do it all himself, according to a recent New York Times analysis of his finances. If Mr. Trump can find a bond company willing to do a deal this big, it will require him to pay the firm a fee as high as 3 percent of the judgment and to pledge collateral.

The bond would prevent the New York attorney general’s office, which brought the civil fraud case against Mr. Trump, from collecting the $454 million while Mr. Trump’s appeal is heard. Without it, the attorney general, Letitia James, is entitled to collect at any moment.

Ms. James is expected to allow Mr. Trump up to 30 days, but if he fails to secure a bond by March 25, and an appeals court denies him extra time, he has a lot to lose. The attorney general’s office could seek to seize some of Mr. Trump’s properties in New York, perhaps even a crown jewel like Trump Tower or 40 Wall Street.

“The attorney general is in the catbird seat and can make this a very unpleasant experience for Trump,” said Mark Zauderer, a partner at the law firm Dorf Nelson & Zauderer who is a veteran New York business litigator and has secured many appeal bonds.