New insight into his business dealings that further undermined his long-cultivated image as a wildly successful businessman was offered by the six years of former President Donald J. Trump's tax records released by House Democrats on Friday.

Thousands of pages of tax documents, including individual returns for Mr. Trump and his wife, were released on Friday. In the first three years of his presidency, Mr. Trump paid over a million dollars in federal income taxes, but did not pay any in 2020.

The document disclosure drew rebukes and threats of retaliation from Mr. Trump and his Republican allies in Congress, who suggested that once their party takes over the House on January 3, they may seek to disclose tax returns filed by Democratic politicians.

According to the documents, Mr. Trump violated his promise to donate his salary as president at least in 2020. The change in the tax law may have caused Mr. Trump's tax bill to go up.

The decision to release the returns had been weaponized by Mr. Trump.

He wrote that the tax returns show how successful he has been and how he has been able to use depreciation and other tax deductions as an incentive for creating thousands of jobs.

The returns show little success for Mr. Trump in his business dealings. Even as he continued to cash in on his assets, Mr. Trump reported heavy losses from his own businesses.

The New York Times obtained decades of Mr. Trump's tax information on Friday.

According to tax returns reviewed by The Times, Mr. Trump had more than $24 million in taxable income in the last year of his presidency. He paid over a million dollars in federal taxes, almost all of it as president.

The gains from the sale of an investment his father made in a Brooklyn housing complex became part of Mr. Trump's inheritance.

A report with top line numbers was released by the committee last week. Tax documents gave new insight into the president's spending and income.

According to the documents, the effect of his inheritance was greater than previously reported.

The tax itemization shows that Mr. Trump lost money on the sales of his business properties. A total of $1 million in assets or equipment sold at a loss by two of his business entities, and another $1 million loss for bailing his son out of a failed business.

While in the White House, Mr. Trump received tens of thousands of dollars in dividends from trusts that had been established for him when he was a child.

Tax returns are one of the most private documents in the US. Congress doesn't take action to get and release them.

Democrats sought Mr. Trump's returns out of concern about potential conflicts of interest after he broke with tradition and refused to release his returns. They were able to get to the bottom of the policy of auditing presidents and vice presidents through their oversight powers.

After years of legal battles, the final release came.

Democrats said the disclosure was necessary because of the president who refused to release his taxes.

Donald S. Beyer Jr., a member of the Ways and Means Committee, said in a news release that Trump acted as though he had something to hide. The public will be able to see that Trump used questionable or poorly substantiated deductions and a number of other tax avoidance schemes as justification to pay little or no federal income tax.

ImageRepresentative Richard E. Neal speaking with other members of the panel while sitting on the dais.
Representative Richard E. Neal of Massachusetts, center, the Democratic chairman of the Ways and Means Committee, which released Mr. Trump’s tax returns.Credit...Haiyun Jiang/The New York Times
Representative Richard E. Neal speaking with other members of the panel while sitting on the dais.

Republicans said that Democrats had set a dangerous precedent. On Friday, the Republicans issued a report with detailed complaints about the process of releasing the documents.

The chairs of both the House Ways and Means Committee and the Senate Finance Committee will be able to target and make public the tax returns of private citizens, political enemies, business and labor leaders, or even the Supreme Court justices themselves.

Mr. Trump said he would retaliate.

He said in his Friday news release that the Democrats should not have done it, the Supreme Court should not have approved it, and it will lead to horrible things for many people. The USA divide is going to get worse. The Radical Left Democrats have weaponized everything.

The $400,000 salary that comes with the job would not be taken by Mr. Trump. He said he would give up his salary if he became president.

Mr. Trump donated his salary in his first three years in office. During his last year in office, Mr. Trump reported heavy business losses and no federal tax liability.

The National Park Service was the first agency to receive Mr. Trump's salary. The tax documents show that Mr. Trump reported more than two million dollars in donations in both of the last two years.

The tax law Mr. Trump signed in late last year appears to have produced mixed results for him. He probably had an advantage at tax time because of the provisions, including the scaling back of the alternative minimum tax.

The limit on the so-called SALT deduction, which disproportionately hit higher-earning people, was included in the law. State and local taxes were paid by Mr. Trump in the year 2019. He was only able to deduct 10% of the taxes he paid on his federal income tax return because of the limits on the state income taxes.

ImageA police vehicle parked in front of Trump Tower in New York.
Mr. Trump’s tax returns reported heavy losses from his own ventures, even as he continued to cash in on assets he had inherited.Credit...Dakota Santiago for The New York Times
A police vehicle parked in front of Trump Tower in New York.

There are thousands of pages of Mr. Trump's return. He has changed accountants to make them.

The accounting firm Mazars USA prepared Mr. Trump's taxes for years. Donald was listed on the former president's tax return as his accountant.

The firm ended its relationship with Mr. Trump and his businesses this year because it couldn't keep up with his financial statements.

Mazars and Trump began to distance themselves from each other in 2020. Mr. Trump had an accounting firm prepare his taxes.

There are new questions about the audits Mr. Trump has faced in and out of office.

Democrats on the Ways and Means Committee downplayed the effect that a long-unresolved audit had on audits. A report by the nonpartisan Joint Committee on Taxation, which analyzes tax policy for Congress, stated that an audit of Mr. Trump's 2015 return had stopped because of a "complexity of issues being worked for tax years 2009 through 2013)."

The report doesn't reveal anything about the audit of 2009. According to an investigation by The Times in 2020, Mr. Trump demanded and received an income tax refund totaling $72.9 million, all of the federal income tax he had paid on his first rush of cash from "The Apprentice"

Mr. Trump had abandoned his stake in his casino businesses that year. It's known as a "quickie refund" because a taxpayer gets it immediately without any questions asked. The audit had not been fixed by the time Mr. Trump took office.

The committee reports released last week didn't mention whether the unresolved issues from the beginning of the decade had slowed down the presidential audit program. When there are unresolved disputes from previous years, the I.R.S. doesn't complete new audits.

Steven M. Rosenthal is a former staff member of the Joint Commission on Taxation.

Mr. Rosenthal is a senior fellow at the Urban-Brookings tax policy center.

Alan Rappeport reported.