Some H&R Block customers who procrastinated until the final day to file their taxes experienced frustrating outages on Sunday, according to the company and Downdetector. The issue, affecting desktop software users, was resolved by Monday afternoon, as stated by H&R Block's support account on X (formerly Twitter).

The problem began around 9 pm ET on Sunday, with Downdetector receiving nearly 1,700 outage reports at its peak. The timing was particularly inconvenient for taxpayers, as the deadline to file for 2023 was set for Monday at 11:59 pm. The Internal Revenue Service (IRS) had anticipated a substantial influx of returns in the final days, with multiple filers relying on online services such as H&R Block.

The outage primarily affected desktop software users, while the company's website remained unaffected. H&R Block advised customers to either refile their taxes or print, file, and mail the form to the IRS. However, some frustrated customers expressed on social media that they preferred e-filing for its convenience, rather than mailing physical copies.

In addition to the filing issues, some customers reported multiple charges when attempting to file their taxes. H&R Block's support account assured users that the temporary authorization holds would typically expire in 3-5 business days, with no actual charges being made.

For H&R Block customers who encounter technical glitches preventing e-filing while owing money to the IRS, the company advised printing out the 1040-V voucher and mailing it with the payment before the midnight deadline. Alternatively, taxpayers can seek an automatic six-month filing extension by completing and submitting the appropriate form.

By 4 pm ET, affected customers were relieved from the need for last-minute post office visits. H&R Block confirmed that clients were notified through an in-product message and customer service outreach that they could now e-file their tax returns.

It is essential to note that taxpayers in Maine and Massachusetts have until April 17 to file and pay their taxes. This is due to the Patriots' Day holiday being observed on April 15, while April 16 marks the Emancipation Day holiday in the District of Columbia, as per the official IRS website.

CNN has reached out to the IRS for an official comment on the matter, and this report has been contributed to by Jeanne Sahadi of CNN.