WASHINGTON (WOOD) — The Internal Revenue Service stopped accepting e-filed tax returns on Wednesday following a hardware failure.

According to the IRS, the hardware failure happened Wednesday afternoon and affected several tax processing systems including the e-file system. Although IRS.gov remains available, a number of the services on the site are not working including “Where’s My Refund.”

The IRS expects some systems to remain out of service until sometime Thursday, but doesn’t anticipate “major refund disruptions.” They expect that 9 out of 10 taxpayers will still receive their refunds within 21 days.

Taxpayers can continue to send electronic returns to companies that serve as middlemen between taxpayers and the IRS. But those companies have to hold on to the tax returns until the IRS systems are up and running again, the IRS said.

Taxpayers who have already filed their tax returns do not have to take any additional action, according to the IRS.