Check Washing Fraud via Postal Mail
How thieves intercept cheques from outgoing mail and chemically alter the payee name or amount, depositing the modified cheque fraudulently while the original sender remains unaware.
Part of: Check Washing Fraud
Last reviewed: 8 June 2026
Check washing is a specific form of mail fraud that targets cheques intercepted from outgoing or in-transit mail. Using common chemicals available from retail stores, fraudsters erase the ink used for the payee name and amount fields while leaving the bank routing number, account number, and signature intact. The cheque is then rewritten to a new payee for a larger amount and deposited into a fraudulent account.
The postal channel is central to this fraud because most victims who still write cheques do so for bill payments they mail to utility companies, rent, or personal payments. A cheque left in a roadside collection box or a residential outgoing mail slot is particularly vulnerable.
Victims discover the fraud only when their bank statement reveals a cleared cheque for an amount they did not write to a payee they did not intend, often after the fraudulent funds have already been withdrawn.
How this scam works on postal mail
A fraudster targets an outgoing mail collection point — a blue USPS collection box, a building's outgoing mail area, or a residential mailbox with a raised flag. Cheques are extracted, photographed or copied, and treated with chemical solvents to remove the payee name and amount.
The altered cheque is rewritten with a new payee name and a much higher amount, then deposited via mobile cheque deposit into a mule account or passed through a bank branch. Funds are rapidly withdrawn or transferred before the fraud is detected.
The original cheque writer's account is debited for the altered amount. The process of recovery is lengthy, requiring bank fraud investigation and often leaving the victim's account disrupted for weeks.
Common red flags
- Bank statement shows a cleared cheque for an amount you do not recognise to a payee you did not select
- A cheque you mailed did not reach its destination within the expected timeframe
- Your bank notifies you of a potentially fraudulent cheque that has been flagged
- You notice cheques missing from your cheque book sequentially after mailing them
How to protect yourself
- Use a gel pen or fraud-resistant ink when writing cheques — these resist the chemical washing process far better than ballpoint ink
- Avoid depositing cheques in roadside collection boxes — use post office counters or hand delivery where possible
- Consider switching to electronic bill payment to eliminate cheque mail risk entirely
- Monitor bank account transactions regularly for unfamiliar cheque clearances
- Use the USPS Informed Delivery service to preview expected mail items daily
How to report it
- Report to the USPS Postal Inspection Service at postalinspectors.uspis.gov
- File a claim with your bank immediately upon discovering the altered cheque
- Report to the FTC at reportfraud.ftc.gov and IC3 at ic3.gov if significant funds were lost
Frequently asked questions
Will my bank reimburse me for a check-washing loss?
Many banks have fraud recovery procedures for altered cheques, but outcomes vary. Report the fraud to your bank immediately in writing, preserving all records. Time is important — the sooner you report, the better the chance of recovery.