The Internal Revenue Service's new free e-filing program is giving some Americans yet another reason to hate tax season.

Less than a month old, the alliance between the IRS and private tax preparation firms that was designed to encourage more Americans to file their tax returns online is drawing some sour reviews.

Among the gripes: Some taxpayers said they have been charged for services they thought were free. Others said they ran into technical problems and gave up trying to file their return after hours of trying. Still others complain that they had to buy additional services to get the free tax-filing service.

Computer programmer Rance Naffziger of Tucson got so frustrated while trying to file his return electronically last month that he ended up filing a paper return by mail.

"I know electronic filing is supposed to be the wave of the future, but I figure I can wait another year," he said. "I'm happy knowing that the paper copy I sent in stands a decent chance of being read by a government official and having them get back to me."

IRS officials acknowledge there have been problems with the fledgling service, but say the complaints account for a tiny fraction of e-filing volume and are largely attributable to growing pains. "This is obviously new for all of us," said Terry Lutes, director of electronic tax administration for the IRS. "It is a learning experience for us and a learning experience for some of the companies."

The free e-filing initiative is part of an IRS program that's been in the works for more than a year. The agency, which had once contemplated providing free electronic filing direct to the public, agreed late last year to offer the service through a partnership with several private firms.

The IRS' partners range from brand names such as H&R Block Inc., Intuit Inc. and CCH Inc. to relative unknowns such as ESmartTax and The partners agreed to offer free e-filing to at least 60% of the nation's taxpayers in return for the marketing boost involved in being an IRS affiliate.

Consumer groups were suspicious of the plan, saying that tax firms were likely to use it as a way to market other, for-fee services.

But complaints from consumers have focused on other issues, including software glitches and getting charged for services they thought were free.

Some taxpayers may have been charged for what they thought was a free service because the 17 firms involved in the program are allowed to change their qualification standards on short notice. For example, some offered free e-filing only to taxpayers earning less than a set threshold or to those above or below a certain age, while others offered free e-filing only to residents of specific states. But a few firms already have changed their criteria, knocking out eligibility for those age 45 or over or New York residents, for instance.

The result: A taxpayer who started a return but didn't complete it immediately could find a site's free offer was rescinded before the tax return was filed. That appears to have forced some taxpayers to cancel the process and start over, or pay a fee for a service they thought would be free.

"The companies' offerings are changing," Lutes said. "We were uncomfortable with this initially but realize that these companies are not charities. We had to give them some wiggle room."

Stephen Ryan, general counsel for a group representing the e-filing firms, said the tax preparation firms in the partnership agreed to provide refunds in these situations.

In other cases, the fee could have been triggered by taxpayer errors. If taxpayers start the process at one of the tax firms' Web sites -- rather than the IRS Web site at -- they may be charged for the service.

Naffziger of Tucson suspects that's why, which says it offers free e-filing to all Arizona residents, was about to charge him $36.50 for filing his return. When he tried to edit his return or delete it so he could start over, the site wouldn't let him fix or delete his information.

"When I selected the prompt saying edit an existing return, it just refreshed the screen," he said. "It wouldn't let me go back in there."

Naffziger sent the site an e-mail asking how he could make the system accept his changes. When he got no response, he gave up.

Stan Kistner, a Florida retiree, had a different problem with FreeTaxUSA. When he entered data from his 1099 forms, which report income from dividends and interest, it showed up on the electronic tax form but not on the summary page that included all the data that would be filed with the IRS.