The federal government collects enough information about most American households to mail out a completed tax form that people would simply need to verify, sign and return. President Ronald Reagan proposed a version of just such a system. In 1998, Congress passed a law instructing the I.R.S. to develop such a system by 2008. President Barack Obama endorsed the concept during the 2008 presidential campaign. It still hasn’t happened.

The explanation is sad but not surprising. The most vocal opponent of simplicity is Intuit, the maker of TurboTax, which has spent millions of dollars lobbying against efforts to reduce demand for its services. The company draws support from conservatives worried that making it easier to file taxes would make it easier to raise taxes.

Since the early 2000s, the government has required Intuit and its competitors to offer free tax-filing software to the 70 percent of taxpayers with the lowest incomes. The legislation requires the I.R.S. to continue the Free File program rather than developing its own. Senator Ron Wyden, the Oregon Democrat who is co-sponsoring the Senate version of the bill, said on Wednesday that the I.R.S. would retain the authority to end the Free File program. But a number of independent experts, including the National Consumer Law Center, said the bill removed that exit ramp.

But only about 3 percent of taxpayers use the programs.

Intuit and its allies, including proponents of the legislation, say that it’s cheaper and better for the government to let private companies run the system. But companies have little incentive to advertise the availability of free filing or to make the system easy to use. Indeed, they have every reason to steer people away from the free products. That is how they make money.

As a result, the government is saving taxpayer money at the expense of those taxpayers.

There is evidence that automatic payment systems can make it easier to raise prices. A 2009 study found agencies raised toll rates after the adoption of E-ZPass, perhaps because drivers were less likely to object if they were unaware of the increases. B ut an automatic filing system also might help taxpayers to save money. For example, almost a quarter of eligible households don’t claim the earned-income tax credit.