Washington CNN  — 

With many of its employees working from home due to the coronavirus pandemic, the Internal Revenue Service has had to move a lot of unopened mail into trailers – just as many people are sending in paper tax returns.

“There is so much mail that the Post Office can’t hold it,” Sunita Lough, deputy commissioner for services and enforcement at the IRS, said during a panel webcast by the Urban-Brookings Tax Policy Center last week.

“So we are literally holding it in trailers until our employees can get back,” she said.

That won’t hold up most individual tax filers, 90% of whom file their taxes electronically, but it could cause delays in processing and refunds for those who use paper. That includes business tax returns and individuals’ amended tax returns.

Lough’s comments were first reported by Politico.

To help alleviate the delay in processing mail, the IRS is allowing people to send documents that they usually send in the mail via fax and email as long as certain requirements are met, she said.

The agency has also extended various tax filing and payment deadlines. Individuals have until July 15 to file their 2019 tax returns.

As of April 10, the IRS had received about 13% fewer individual tax returns this year compared to 2019 and processed 15.5% less.

In addition, the IRS has been tasked with sending out stimulus payments to about 90% of households, as outlined in the $2.2 trillion CARES Act signed into law last month.

Last week, it sent out the first round of stimulus payments, directly depositing money to roughly 80 million people’s bank accounts. Others will receive paper checks in the mail, which are expected to start going out this week – but it could take months before all of the money to be disbursed.

As of early April, all IRS processing centers have shut down due to stay-at-home orders. It shut down its in-person tax preparer sites in March.

The IRS has said these temporary closures will not affect its ability to deliver the stimulus payments. The agency did not respond Monday when asked for further comment.