Business checks are prime targets in mail-theft check fraud: secure outgoing mail and cut paper payments

FinCEN’s 2023 alert describes a nationwide surge in check fraud built on mail theft, from blue collection boxes, cluster mailboxes and stolen USPS Arrow Keys. Business checks are especially valuable to thieves because accounts are well funded and fraud may be noticed later.

Source facts

FinCEN’s February 27, 2023 alert describes a nationwide surge in check fraud schemes targeting the mail. From March 2020 through February 2021, the Postal Inspection Service received 299,020 mail theft complaints, a 161 percent increase, and check-fraud suspicious activity reports reached over 680,000 in 2022, nearly double the previous year.

Criminals steal personal, business, tax refund and government benefit checks, but FinCEN notes business checks may be more valuable because business accounts are often well funded and fraud may take longer to notice. Check washing uses chemicals to remove the original ink and replace the payee and often the amount.

Thieves target USPS blue collection boxes, unsecured residential mailboxes and privately owned cluster box units at apartment complexes and high-density commercial buildings, using forced entry, fishing devices or authentic or counterfeit USPS master keys known as Arrow Keys. FinCEN reports cases of criminals violently targeting mail carriers to steal those keys.

Applicability

Use this for any organization that still sends or receives paper checks, and for buildings with on-site mailbox banks. The alert is written for financial institutions; the business steps below are DSE recommendations.

DSE recommendation

DSE recommends reducing mailed checks and moving the remaining outgoing payments out of unattended mailboxes. Pay vendors and payroll electronically where possible, hand outgoing checks to staff at a post office counter rather than leaving them in a box overnight, and ask your bank about check-verification services for issued checks. Property managers should cover cluster mailbox areas with lighting and recorded video and report forced or tampered units to the Postal Inspection Service.

Verification

Reconcile business bank accounts daily for altered or unexpected checks, track how many checks are still mailed each month, and review mailbox-area camera views to confirm the boxes and approach path are visible day and night.

Official reference

FinCEN — Alert on Nationwide Surge in Mail Theft-Related Check Fraud Schemes Targeting the U.S. Mail (FIN-2023-Alert003). Reviewed October 18, 2026.