The Internal Revenue Service will resume sending balance-due notices to U.S. taxpayers this month after halting them in May because of a massive pandemic-related mail backlog.

The IRS shut several mail processing centers in the spring due to COVID-19, and the ensuing backups forced the agency to store millions of pieces of mail temporarily in trailers.

“The mail backlog is now caught up enough to account for the timely mailed payments,” the IRS said in a statement Friday. Taxpayers will begin seeing updated notices in late October or early November, the agency said.

The notices alert individual taxpayers that they have a balance due and what their payment options are. Some also tell taxpayers that they may be subject to a lien if they don’t pay promptly, and others note that the recipients must pay immediately or face a levy on their state income tax refunds.

The IRS said payment plan options are available for individuals unable to pay immediately, but that interest and penalties will continue to accrue. Some filers affected by the pandemic may be able to avoid penalties if they were subject to circumstances beyond their control, the agency said.