He added that some of the aims of return-free filing, including lower prices and simplified filing, could be provided by the private sector. The I.R.S. already works with Intuit and other tax preparation companies on a system called Free File, which lets people with low incomes use software like TurboTax free. And rather than download people’s financial data from government sources — which Mr. Williams said might not be very secure — Intuit prefers to connect its systems to banks, employers and other private companies to obtain taxpayers’ information, he said.

Dennis Ventry, a professor at the School of Law at the University of California, Davis, who has studied the issue, said that while Free File and Intuit’s integrations with private companies were beneficial, they won’t be nearly as helpful as a government program to reform tax filing.

Mr. Ventry said that if return-free filing were operated nationally, tens of millions of people with simple tax situations might have to do just a few minutes of work at tax time every year. The I.R.S. would send them a tax return that had already been filled in with their financial data, and if everything looked in order, they would file it either through the mail or electronically. The return would be completely voluntary. People who disputed the I.R.S.’s calculation would be able to do their taxes the old-fashioned way. Tens of millions of additional taxpayers with more complex returns would be able to save time by downloading all the financial information that the government has collected about them during the year. You would be able to do your return without hunting for every stray W-2 or 1099 in your household.

“It can help all 145 million taxpayers,” Mr. Ventry said.

But Intuit’s opposition to return-free filing has been ferocious. In the last five years, according to disclosure documents, Intuit spent nearly $13 million on federal lobbying. That is about the same amount that companies many times its size have spent on lobbying. Apple, which has an annual income about 40 times that of Intuit, also spent about $13 million on lobbying in the same period. While documents show that Intuit lobbies on several issues, including immigration, cybersecurity and intellectual property law, the company’s largest lobbying contracts all involve the issue of tax administration.

More than a decade ago, Mr. Bankman helped create a California program known as ReadyReturn that precalculates some residents’ state tax returns. It received little marketing and fewer than 100,000 people used it at its peak — yet every year in surveys run by California’s Franchise Tax Board, more than 95 percent of those who had used ReadyReturn said they would use it again. Mr. Bankman said that people who used the system saved about $30 a year in costs and about 30 minutes in time. Seeing the success of the program, tax authorities in other states began contacting Mr. Bankman for help in setting up a similar plan.