Taxpayers filing their taxes online could face serious delays in getting a refund.
An unspecified number of online tax processing systems, including the "Where's My Refund" tool, were down on Wednesday as a result of a "hardware failure," the IRS said in a statement.
"The IRS is still assessing the scope of the outage," the agency said in a statement on Wednesday. "At this time, the IRS does not anticipate major refund disruptions; we continue to expect that 9 out of 10 taxpayers will receive their refunds within 21 days."
A spokesperson for the IRS would not release further details.
Busy Time Of The Year
The IRS told ABC News that it would not be able to release the filing numbers for this tax season, but according to previously released figures on the IRS site, the first week of February is a relatively busy time for e-filing.
In 2014, 26.1 million people filed online during the week of Feb. 7. That number increased to 26.5 million during the week of Feb. 6, 2015.
In 2015, $66.1 billion in refunds were issued during the week of Feb. 6.
Those numbers mark a significant increase from the week prior. Only 10.4 million returns were filed online during the week of Jan. 31, 2014 and 13.3 million were filed during the week of Jan. 30, 2015.
Getting It Fixed
When the outage was announced on Wednesday, the IRS said in a statement that its site would be down through Thursday. No additional information was given.
What To Do In The Meantime
The IRS said taxpayers can still file their tax returns and send the forms to e-filing providers while the systems are down.
The e-file companies will hold onto the tax returns they receive until they are able to file electronically when the systems are back up, the IRS said.
H&R Block said in a statement to ABC News that the company's systems have not been impacted by the IRS hardware failure.
"We will submit returns to the IRS when it is ready to resume accepting e-filed returns. H&R Block clients who have provided their e-mail address will automatically receive an e-mail notification when their tax return has been accepted by the IRS," according to the statement.