Just as the tax season is starting to bear down on us, do-it-yourself filers using Intuit’s popular TurboTax learned Friday morning that the company halted work on all state tax returns after agencies discovered a spike in fraudulent returns.

And then hours later, Intuit said they had resumed the filings.

The Mountain View-based company had put the brakes on processing the returns after receiving an alarming number of complaints from states about documents being filed using stolen personal data. In a statement, Intuit said it was taking a “precautionary step,” starting Thursday, of “temporarily pausing its transmission of state e-filing tax returns.

But late Friday afternoon, after working with its security experts, Intuit issued another press release, saying it had resumed e-filing of state income tax returns as of 3 p.m.

“Nothing is more important to us than the safety of our customers’ data,” said Brad Smith, Intuit president and chief executive officer. “We are taking this issue very seriously and from the moment it emerged it has been all-hands-on-deck. We’ll continue to remain vigilant, but I am more than pleased that we were able to resume transmission for our customers within about 24 hours.”

Intuit said that after conferring with its security consultants at Palo Alto-based Palantir, it “believes that these instances of fraud did not result from a security breach of its systems. As a result of that examination, which is ongoing, Intuit implemented targeted security measures to combat the type of fraudulent tax activity that it is seeing.”

The problem has not spread over to the federal level because the Internal Revenue Service reportedly has better online security systems in place. It was unclear which states had reported fraud cases, although officials with California’s Tax Franchise Board said in a statement Friday that “at this moment, we do not believe that California taxpayers have been impacted by this issue. So far, we have not identified any unusual fraud activity.

Coming just one day after Blue Cross Blue Shield insurer Anthem said hackers had gained access to the Social Security numbers and other personal information of about 80 million people, news of the Intuit showdown was disconcerting to many of its customers.

“I’ve used TurboTax for years and this really concerns me,” said Arthur Kelly, 58, a computer scientist from Palo Alto. “If someone files a fraudulent return in your name, which is a form of identity theft, it would be hard to straighten that out. The problem is there are more and more places that now have your Social Security number, so we’re all increasingly vulnerable to hackers.”

Intuit said that at least so far, there apparently was no security breach of its systems. Instead, the company believes personal information was stolen elsewhere and used to file returns on TurboTax. Still, customer like Kelly are worried.

“To fix a systemic problem like this is very difficult,” he said. “Because it’s a cat-and-mouse game: even as companies and even the IRS improve their security, hackers will keep coming back.”

In its own statement, the Internal Revenue Service said “it continues to accept and process tax returns and refunds, and the filing season has started successfully.” The IRS said “taxpayers should continue to file their tax returns as they normally would.”

Contact Patrick May at 408-920-5689 or follow him at Twitter.com/patmaymerc