RELATED: USPS Will No Longer Let You Do This, Effective Immediately. The White House is gearing up to mail at-home COVID tests to people across the U.S. for no charge through the USPS, in accordance with a new plan from President Joe Biden. The government is allowing people to sign up for kits through a sign-up page on the Postal Service’s website—which is now up and running as of Jan. 18, a day earlier than planned.ae0fcc31ae342fd3a1346ebb1f342fcb According to CNN, the White House has said it already has tens of millions tests ready to ship. And the USPS has indicated that it has been preparing for this, ever since the administration first announced its plan in December. “We have been working closely with the Administration and are well prepared to accept and deliver test kits on the first day the program launches,” Postmaster General Louis DeJoy said in a statement, per CNN. RELATED: USPS Is Making This Permanent Change. Under the new plan, each household can sign up to receive four tests per residential address. But this stipulation is causing some people to miss out on their allotment. According to WHYY, a public FM radio station serving the Philadelphia region, a glitch with the USPS’ website is failing to allow it to recognize different apartments in some buildings as separate residential addresses. James Snelling, a resident from Francisville, Philadelphia, told the news outlet that when he entered his address on the Postal Service’s website, he was met with an error message telling him that his address had already ordered its allotted amount of tests, despite Snelling living alone. But he did live in a multi-unit building, where one of his neighbors had ordered tests for their apartment. Others on Twitter have acknowledged running into the same issue. “Looks like the USPS test ordering portal is either glitching, or doesn’t differentiate between different units in apartment/condo buildings. Just got this error message,” writer and researcher Natalie Shure tweeted on Jan. 18, providing a screenshot of the same message Snelling received. “Our records show that at-home COVID-19 tests have already been ordered for this address. We are unable to process duplicate orders for the same address,” the error page reads. Despite a number of complaints being lodged on Twitter and through various news reports, a spokesperson for the USPS told WHYY that the issue was only minor. “The Postal Service is seeing very limited cases of addresses that are not registered as multi-unit buildings which could lead to COVID test kit ordering difficulties,” USPS spokesperson David. A Partenheimer told the news outlet in an email. “This is occurring in a small percentage of orders.” But many critics have noted that the four-test limit and this glitching issue, even if minor, is largely affecting lower income residents—who are most at need for free tests—because they are more likely to live in apartments or under one roof with extended families. “The issue is if you’re lower income, and you have more than one family in the same household at that same address,” Georges Benjamin, the executive director of the American Public Health Association, told Politico. RELATED: For more up-to-date information, sign up for our daily newsletter. This is not the only criticism that has been launched toward the USPS recently. Many communities and people across the U.S. have reported significant mail delays over the past few weeks. Maryland resident Derek Reynolds told CNN that he had gotten his mail delivered last week for the first time in nearly three weeks. “It’s a very weird and frustrating situation to have things you know are coming but you just don’t know when they are ever going to arrive,” Reynolds said. Congresswoman Eleanor Holmes Norton also sent a letter to the USPS on Jan. 12, citing concerns about mail delays in Washington, D.C. Norton said this problem makes her concerned about how quickly the Postal Service will be able to deliver the free COVID tests. “There are households where there has been no mail delivered for days,” she told CNN. “If we can’t get the mail, how are we going to get these COVID tests?” Reynolds voice a similar concern. “I would be very worried about getting a test in any kind of timely manner,” he told the news outlet. The USPS said it is working specifically to ramp up operations for delivering these tests, however. According to CNN, the agency is setting up 43 centers that will pack and ship tests, as well as hiring more than 7,000 temporary workers to help with the workload. RELATED: If You Get This Package in the Mail, Don’t Open It, Experts Warn.