Tax filing season will begin in two weeks, the IRS announced Monday, as officials warned of backlogs and the agency’s inability to meet demands for service from taxpayers.

Treasury Department officials on Monday said tax season will again be complicated by the COVID-19 pandemic, which has caused shutdowns of IRS mail centers, staff leave and new rounds of aid that have complicated tax returns.

The start of tax season is in line with past years, but several weeks earlier than the 2021 filing period kicked off. The time period for filing tax returns will run through April 18, a few days later than usual because April 15 is a Washington, D.C. holiday in 2022, marking Emancipation Day.

While the IRS typically enters tax season with a backlog of about 1 million unprocessed returns, that number is several times larger this year, according to Treasury officials, who couldn’t give a precise number. They attributed the increases to pandemic-related issues and COVID-19 aid that complicates returns, such as several rounds of stimulus checks.

While officials still believe the IRS can meet its typical timeline of 21 days to process most refunds, the agency is anticipating long call times and other complications that could frustrate taxpayers.

The officials also tied the agency’s delays and projected service problems to the agency’s funding level. The Biden administration is asking Congress for more funding for the IRS, including $80 billion that’s proposed as part of Democrats’ social safety net and climate package. The funding is an offset in the bill, projected to provide billions in new revenue since it’s mostly marked to help the IRS go after uncollected taxes. It also provides extra funding for taxpayer services, updating the agency’s technology and other support efforts.

Officials urged taxpayers to file their taxes electronically and include information to deposit returns directly into their bank accounts to ensure quicker refunds. They encouraged particular attention for those who’ve received stimulus checks and monthly advance payments of expanded child tax credits, which lapsed last month.

While those monthly payments aren’t going out anymore, beneficiaries can still get the second half of their full-year child tax credits, or up to $1,800 per child, as a refund after the IRS processes their returns.