New York CNN  —  Some H&R Block customers who waited until the last day to file their taxes faced frustrating outages that began Sunday night, according to the company and Downdetector. The outage was resolved by Monday afternoon, the tax preparer’s support account posted on X, formerly known as Twitter. Downdetector, which relies on self-submitted reports to track telecommunication and internet disruptions, reported the problems began around 9 pm ET on Sunday. At its peak, there were almost 1,700 outage reports. The outage came at an inconvenient time for taxpayers, as Monday at 11:59 pm is the deadline to file for 2023. The IRS had expected “tens of millions” more returns to be filed in the last few days, and many tax filers rely on online services such as H&R Block. The bad gateway error prevented some desktop software users from filing their returns, H&R Block said on X. Most self-filing customers use the company’s website, which was not affected by the outage. H&R Block advised customers to either file again or print, file and mail the form to the IRS. But that frustrated some customers on social media, who said they rely on e-filing for the convenience over mailing. CNN has reached out to the IRS for an official comment. Customers posted on social media that their cards were charged multiple times when attempting to file their taxes. The company’s support account on X said the temporary authorization holds customers may see will usually expire in 3-5 business days, and the user will not be charged. Should H&R Block customers encounter a tech glitch that prevents them from e-filing and still owe the IRS money, they can avoid a penalty by printing out the 1040-V voucher and mailing it in with their payment by the midnight deadline. Taxpayers can also apply for an automatic six-month filing extension by filling out and sending in this form. By around 4 pm ET, affected customers were spared from the last-minute trip to the post office. “We have notified our clients via an in-product message and as they reach out to customer service that they can now efile their return,” H&R Block said in a statement to CNN. Taxpayers in Maine and Massachusetts have more time than other states to file their taxes. “Taxpayers in Maine and Massachusetts have until April 17 to file and pay taxes due this year. This is because these states observe the Patriots’ Day holiday on April 15 this year and April 16 is the Emancipation Day holiday in the District of Columbia,” reads the official website of the IRS.