Check Washing Fraud: How Thieves Steal Your Mailed Checks

Imagine writing a check for $42 to pay your water bill — and then discovering that the very same check cleared your bank account for $4,200, made out to a stranger you have never heard of. Nobody broke into your home. Nobody stole your wallet. Someone simply pulled the envelope out of a mailbox and chemically erased the ink.

That trick has a name: check washing. It is one of the oldest forms of bank fraud in America, and it is surging again. In January 2025, the FBI and the U.S. Postal Inspection Service (USPIS) issued a joint public warning that mail-theft-related check fraud is on the rise. Suspicious Activity Reports related to check fraud nearly doubled between 2021 and 2023, and federal investigators say the problem keeps growing as organized theft rings get better at stealing outgoing mail.

Check washing works because of a simple chemistry fact: most ballpoint pen ink dissolves in common household chemicals like nail polish remover or rubbing alcohol, while the check paper itself survives. A criminal who steals a mailed check can erase the payee name and the dollar amount, rewrite both, and cash a check that looks almost untouched. Your signature — the one part of the check they keep — makes the altered document pass inspection.

How Check Washing Works: Step by Step

Step 1: The theft. The fraud begins with access to your outgoing mail. According to the FBI’s 2025 warning, thieves obtain checks through several channels: envelopes left in residential mailboxes overnight or left for long periods, USPS blue collection boxes after the last scheduled pickup, burglaries of postal facilities, robberies of postal employees, and even bribery or collusion with postal workers. That little red flag standing up on your home mailbox is, from a thief’s perspective, an advertisement that outgoing mail is waiting inside.

Step 2: The wash. Once the check is in hand, the thief targets the ink. Using household chemicals — nail polish remover, rubbing alcohol, and similar solvents — they carefully lift the handwritten payee name and amount off the paper. This works because standard ballpoint ink sits on the surface of the paper, while the pre-printed check stock and your signature (which the thieves leave intact, since a matching signature is exactly what makes the forgery convincing) remain.

Step 3: The rewrite. With the check blanked of its original details, the criminal writes in a new payee name — themselves, or an accomplice — and a much larger dollar amount. Some leave blank spaces on the original check to make this easier, which is why experts advise never leaving gaps on the payee or amount lines.

Step 4: The cash-out. The altered check is deposited or cashed, often through accounts controlled by “money mules” recruited online, and the funds are withdrawn fast. Financial institutions are required by regulation to make check funds available quickly — often before the fraud can be detected — so the money is gone before you or your bank realize anything is wrong. Stolen checks are also traded among criminal networks, sometimes sold on dark web marketplaces for cryptocurrency, so one stolen check can feed several layers of fraud.

Step 5: The cover. Because the check still bears your genuine signature and your real account and routing numbers, it can pass automated processing without raising alarms. Since 2004, American banks have exchanged digital images of checks rather than the physical paper, which means no human being routinely compares the handwriting on the payee line against your normal writing. That is a big reason washed checks clear as easily as they do.

Real Cases: What Check Washing Looks Like in Practice

These are not hypotheticals. Documented cases reported by major news outlets show how ordinary mail becomes a direct pipeline to victims’ bank accounts.

In one case reported by ABC7 NY, Carol Perlman mailed a $656 check — and criminals altered it to $9,000. Her bank eventually refunded the money, but only after local media coverage brought attention to the case. In the same report, another victim named Matt Schick dropped a contractor’s payment into a street mailbox; within days, someone had intercepted and cashed it for $7,500.

An even larger case was reported by Fortune magazine: an entrepreneur referred to as Steve mailed a $310,000 payment to the IRS. Thieves chemically washed the check, replacing “IRS” with another name, and deposited it. He was forced to pay his taxes again — including penalties and interest — while still fighting with his bank to recover the stolen funds.

Small businesses are hit especially hard because they mail checks in predictable batches. Fraud rings watch for patterns, such as regularly scheduled payments, so that altered checks look routine. Older adults who still pay bills by mail are also disproportionately targeted.

Red Flags: Signs Your Check May Have Been Washed

A check you mailed never arrived. The payee says they never received payment. Before assuming it was lost, consider that it may have been intercepted.
Your bank shows a cleared check for a different amount or payee. A $42 water bill that cleared for $4,200 is the classic signature of a washed check.
Check images that don’t look like your handwriting. Review the image of the cleared check in your banking app — most banks let you see it. The payee line or amount may be in different ink or handwriting than yours.
Your statement shows small or unfamiliar checks you didn’t write. Thieves sometimes write small test amounts before going big.
A creditor or agency says your payment bounced or was “altered.” The IRS, utilities, and lenders sometimes flag altered checks and return them.
Your mail is regularly tampered with or arrives opened. Mailbox theft rarely happens once — a thief who found checks once will come back.
You receive bank notices about insufficient funds you can’t explain. A washed check for thousands of dollars can overdraw an account you thought was healthy.

How to Protect Yourself: 9 Steps

Write checks with black gel ink. The Postal Inspection Service specifically recommends black gel pens, because the pigment sets into the paper fibers and will not lift with chemicals the way ballpoint ink does. This single habit is the most-cited defense against washing.
Hand mail across the counter or into the lobby slot inside the post office. Never leave outgoing mail in your home mailbox with the flag up, and never leave it in a blue collection box after the last pickup — a box after hours holds everything inside it until morning.
Never leave mail in your mailbox overnight. Bring outgoing mail to the post office as close to collection time as possible, and pick up incoming mail promptly.
Leave no blank spaces. Fill the payee and amount lines completely, and start the written amount at the far left of the line so nothing can be inserted later.
Pay electronically whenever possible. Online bill pay, ACH transfers, and digital wallets eliminate the risk of physical mail theft entirely. Most billers offer electronic payment, and many give discounts for paperless accounts.
Check your bank activity weekly — not monthly. Review every cleared check’s image in your banking app, and turn on transaction alerts. Many banks give you only about 30 days to report fraud on an altered check, so waiting for the monthly statement can cost you your rights.
Follow up with payees. After mailing a check, confirm with the recipient that it arrived and was deposited for the correct amount.
Shred voided and canceled checks. Never toss unused, voided, or canceled checks in the trash — criminals rummage through garbage for exactly this material. Shred them, along with old bank statements.
Ask your bank about security features and Positive Pay. Some check printers add watermarks, void pantographs, security inks, microprinting, and chemically reactive paper. Business accounts can use Positive Pay, which matches presented checks against a list you provide and flags mismatches before money moves.

What to Do If You’ve Been Targeted

If you mailed a check and suspect it was washed, act the same day — timing is everything:

Call your bank immediately using the number on the back of your debit card or on your statement — not a number from a text or email. Report the altered check and ask about closing the compromised account and opening a new one, because the thieves now have your account and routing numbers and can create counterfeit checks or withdraw electronically.
Request copies of the fraudulent checks from your bank and save them as evidence.
File a report with the U.S. Postal Inspection Service at uspis.gov/report or 1-877-876-2455 if the check was stolen from the mail.
File a report with the FBI’s Internet Crime Complaint Center at ic3.gov.
Report fraud to the FTC at ReportFraud.ftc.gov, and file a report with your local police department.
Notify the credit bureaus and consider a fraud alert or credit freeze, since the thieves obtained your name, address, and banking details from the check.
Warn the original payee so they know the payment they were expecting never arrived — and arrange an alternative payment method.

How to Report Check Washing Fraud

Your bank: Call immediately — report the altered check, dispute the transaction, and discuss closing the compromised account. Many banks set a reporting window of about 30 days for altered checks, so do not wait for your next statement.
U.S. Postal Inspection Service: File a mail theft report at uspis.gov/report or call 1-877-876-2455.
FBI Internet Crime Complaint Center: File at ic3.gov, especially when the fraud involves online deposit schemes, money mules, or cryptocurrency resale of stolen checks.
FTC: Report at ReportFraud.ftc.gov — your report feeds law enforcement investigations and helps track fraud patterns.
Local police: File a police report; you may need the report number for your bank’s fraud claim.

The Bottom Line on Check Washing

Check washing turns your own signature into a weapon against you. The chemistry is decades old, but the theft rings are modern, organized, and growing — and the FBI says mail-theft-enabled check fraud keeps climbing. The good news is that the defenses are simple and cheap: a black gel pen, a trip inside the post office instead of the blue box, weekly account checks, and electronic payments wherever you can. And if a check of yours goes missing or clears wrong, move fast — report it to your bank, the Postal Inspection Service, the FBI’s IC3, and the FTC the same day.

Sources

FBI, “Mail Theft-Related Check Fraud is on the Rise,” Public Service Announcement I-012725-PSA (January 27, 2025) — https://www.fbi.gov/investigate/cyber/alerts/2025/mail-theft-related-check-fraud-is-on-the-rise
U.S. Bank, “How to prevent check fraud” — https://www.usbank.com/financialiq/manage-your-household/protect-your-assets/essential-tips-for-preventing-check-fraud.html
Moneywise, “Check washing is now costing Americans over $1 billion each year, says USPIS” — https://moneywise.Com/news/check-washing-is-now-costing-americans-over-1-billion-each-year-says-uspis
ConsumerAffairs, “Warning: Check washing can drain your bank account” — https://www.consumeraffairs.com/news/warning-check-washing-can-drain-your-bank-account-040926.html
LegalClarity, “How to Report Mail Fraud to USPIS, FTC, and FBI IC3” — https://legalclarity.org/how-to-report-mail-fraud-to-uspis-ftc-and-fbi-ic3/

Last reviewed: October 2026

This article is for education only and is not financial or legal advice.