The Trump administration’s latest allegations of mortgage fraud have raised questions about a long-standing housing issue known as owner-occupancy mortgage fraud. But that type of fraud can be difficult to prove, experts say.

President Donald Trump announced in a Truth Social post on Monday night that he was removing Federal Reserve Governor Lisa Cook. He cited allegations made by Federal Housing Finance Agency Director Bill Pulte that Cook committed mortgage fraud by claiming homes in two different states as her primary residence at the same time.

Cook’s attorney on Tuesday said Cook will file a lawsuit to challenge her removal.

“President Trump has no authority to remove Federal Reserve Governor Lisa Cook,” the lawyer, Abbe Lowell, said in a statement.

The Department of Justice has also recently targeted Sen. Adam Schiff, D-Calif., and New York Attorney General Letitia James with similar mortgage fraud allegations.

Here are the key things to know about owner-occupancy mortgage fraud, according to experts.

The main reason a borrower could be motivated to claim a primary residence on a mortgage application is to get a lower interest rate for that home.

Typically, mortgages for a primary residence have lower interest rates and homeowner’s insurance costs, said Keith Gumbinger, vice president of mortgage website HSH.

Mortgage interest rates are generally 0.5% to 1% higher for investment properties than for primary homes, according to Bankrate. Homeowners also typically pay about 25% more for insurance as a landlord compared with a standard homeowners policy, according to the Insurance Information Institute.

Owner-occupied means “you’re going to live there the majority of the time,” Gumbinger said. But there are limited exceptions, including for military service, parents providing housing for a disabled adult child or children providing housing for parents, according to Fannie Mae.

If a homeowner changes primary residences, they need to inform their mortgage lender that the original property is no longer owner-occupied, Gumbinger said.

There are also federal and state tax benefits for primary residences, according to Albert Campo, a certified public accountant and president of Campo Financial Group in Manalapan, New Jersey.

For example, when an owner sells a home and makes a profit, they can take a capital gains exemption worth up to $250,000 for single filers or $500,000 for married couples filing jointly, as long as they meet certain IRS rules, including owner occupancy for two of the past five years.

For tax purposes, a homeowner can have only one primary residence at a time.

When a taxpayer owns more than one home, proving which one is the primary residence is “always based on facts and circumstances,” Campo said. For example, a primary residence is typically where an owner spends most of their time, votes, files their tax returns and receives mail, he said.

A 2023 report from the Federal Reserve Bank of Philadelphia found that more than 22,000 “fraudulent borrowers” misrepresented their owner-occupancy status, out of 584,499 loans originated from 2005 to 2017. The data was based on a subsample from more than 15 million loans originated during this period.

Typically, the fraudulent borrowers took out larger loans and had higher mortgage default rates, the authors found.

However, this type of fraud may be “difficult to detect until long after the mortgage has been originated,” the authors wrote.

“There is a difference between the court of law and the court of public opinion,” Jonathan Kanter, a law professor at Washington University in St. Louis and a former assistant attorney general, told CNBC’s “Squawk Box” last week when asked about Cook. “In the court of law, this is small ball and very difficult to prove.”

“You’d have to establish not only that she filled out the form incorrectly, but she had the specific intent to deceive, to defraud banks, as opposed to just making a mistake,” he said.

During fiscal year 2024, 38 mortgage fraud offenders were sentenced in the federal system, according to the United States Sentencing Commission’s interactive data analyzer. That number is up slightly from 34 offenders in 2023, but down from 426 offenders in 2015, the earliest date in that tool’s dataset. The U.S. Sentencing Commission data does not break out the types of mortgage fraud.

Frontier Airlines is going after customers of Spirit Airlines, whose financial footing has gotten so shaky in recent weeks that it warned earlier this month it might not be able to survive another year without more cash.

Frontier on Tuesday announced 20 routes it plans to start this winter, many of them in major Spirit markets like its base at Fort Lauderdale International Airport in Florida. Frontier overlaps with Spirit on 35% of its capacity, more than any other airline, according to a Monday note from Deutsche Bank airline analyst Michael Linenberg.

Some of Frontier’s new routes from Fort Lauderdale include flights to Detroit, Houston, Chicago and Charlotte, North Carolina. It’s also rolling out routes from Houston to New Orleans; San Pedro Sula, Honduras; and Guatemala City.

Frontier had tried and failed to merge with its budget airline rival several times since 2022.

“I’m not here to talk about M&A,” Frontier CEO Barry Biffle said in an interview with CNBC on Tuesday when asked whether Frontier would buy Spirit. Biffle said he expects that Frontier would pick up the majority of Spirit’s market share if Spirit collapsed.

Both carriers have struggled from changing customer tastes for more upmarket seats and trips abroad, an oversupply of domestic capacity, and higher labor and other costs. Spirit’s situation has become more dire however, after it emerged from four months of bankruptcy protection in March facing many of the same problems.

Ultra-low-cost airlines are also challenged by larger rivals like United Airlines, American Airline and Delta Air Lines that have rolled out their own no-frills basic economy tickets but also offer customers bigger choices of destinations and other perks onboard like snacks and beverages.

Stock prices of rival airlines surged after Spirit’s warning earlier this month.

Biffle said the carrier wants to become the country’s largest budget airline and has rolled out loyalty matching programs to grab more customers. Frontier’s capacity was slightly smaller than Spirit’s in the second quarter, through the latter had slashed its flying by nearly 24% from a year earlier, while Frontier was down only 2%.

Spirit last week said it drew down the entire $275 million of its revolver and while it reached a two-year extension on its credit card processing agreement with U.S. Bank N.A., it agreed that it would hold back up to $3 million a day from the carrier.

The airline lost $245.8 million in the second quarter. Frontier lost $70 million.

Spirit has been looking for ways to slash costs, including furloughing and demoting hundreds more pilots and cutting unprofitable routes. Hundreds of flight attendants are on unpaid leaves of absence.

Spirit CEO Dave Davis said in an Aug. 12 staff memo after its “going concern” warning that “the team and I are confident that we can build a Spirit that will continue to provide consumers the unmatched value that they have come to expect for many years to come.”

The carrier reached a deal with bondholders who agreed to convert debt to equity in its Chapter 11 bankruptcy, but it didn’t cut other costs like renegotiating aircraft leases. Leasing firms have been reaching out to rivals in recent weeks to gauge whether competitors would take any of the Airbus planes that are in Spirit’s hands, according to people familiar with the matter, who asked to speak anonymously because the talks were private.

— CNBC’s Phil LeBeau contributed to this report.

Cracker Barrel tried to reassure customers Monday that its values have remained the same after it received criticism following a new logo reveal and general brand refresh.

The company promised customers in a statement that while its logo may be different, its values — “hard work, family, and scratch-cooked food made with care’ — are not.

“You’ve shown us that we could’ve done a better job sharing who we are and who we’ll always be,” the statement read, adding that Cracker Barrel will remain “a place where everyone feels at home, no matter where you’re from or where you’re headed.”

Last week, the company unveiled a new logo that no longer features a man leaning against a barrel or the words ‘Old Country Store.’ Instead, it featured the company’s name, in a color scheme that it said was inspired by the chain’s scrambled eggs and biscuits.

The change was part of a ‘strategic transformation’ that aimed to update the chain’s visual elements, spaces, food and retail offerings. The company’s shares are down about 8.5% since the reveal ignited criticism, especially from those in conservative circles.

Donald Trump Jr., the president’s son, amplified a post Wednesday suggesting that the logo change was intended to erase the American traditions aspect of the branding and make it more general and lean into diversity, equity and inclusion efforts.

On Monday, the chain also shared an update on the man in the original logo, Uncle Herschel, who is said is still featured on menus and road signs and in stores.

‘He’s not going anywhere — he’s family,’ the company said in the statement.

Cracker Barrel said its focuses remain country hospitality and generous portions of food at fair prices. The refresh, it said, was to ensure the restaurant will be there for the next generation.

‘That means showing up on new platforms and in new ways, but always with our heritage at the heart,’ it said.

‘We know we won’t always get everything right the first time, but we’ll keep testing, learning, and listening to our guests and employees.’