"For the second consecutive year we've seen a late start to the tax season, resulting in the majority of our business occurring in the fiscal fourth quarter," the company said in a statement on Thursday.
"Given the seasonal nature of our business, the focus remains on our performance for the full year."
H&R Block posted third-quarter revenue of $200 million, and said another $277 million of revenue is being "shifted" into the fourth quarter as a result of the delay.
The company's third-quarter loss came in at a whopping 77 cents per share, versus analysts' expectations for a loss of 11 cents per share.
(Read more: 7 tech tools to make tax prep less frustrating)
It is uncertain how analysts will compare these numbers to the consensus Thomson Reuters estimate of $519 million in revenue, but any way you add it up revenue did fall short of estimates.
Bottom line: Even with the IRS delay, H&R Block's results most likely came in shy of estimates. The question is by how much did H&R Block miss.
H&R Block shares dropped as much 2 percent in after-hours trading following the announcement.
—By CNBC's Juan Aruego.