Check Washing: How to Protect Your Mail and Bank Account

Check washing involves altering a genuine check to change its payee or amount. A mailed payment may be stolen, changed and deposited by someone else. Knowing the warning signs, protecting your mail and reporting suspicious payments promptly can reduce risk, but no pen or reporting deadline guarantees protection or reimbursement.

1. How does check washing actually work?

A thief may take a legitimate check from the mail and change the written payee or amount.

Genuine account information may remain, so an altered check can look familiar at first glance. The Postal Inspection Service says some stolen checks are chemically washed, while others are copied or scanned to make fraudulent checks. Review the payment details rather than relying only on whether the paper looks authentic.

To reduce the chance that a mailed payment is intercepted, place outgoing mail in a collection box before its last pickup or take it to a Post Office. Retrieve delivered mail frequently and arrange for mail to be held or collected while away. For related warning signs, see our guide to USPS delivery scams. USPIS check-washing guidance.

The scale of mail-related check fraud is documented, but the figures need careful interpretation. FinCEN’s September 2024 analysis examined the six months after its 2023 alert. In that review, FinCEN reported, according to its analysis, 15,417 Bank Secrecy Act reports from 841 financial institutions, involving more than $688 million in reported suspicious activity. These are reports and suspicious-activity amounts, not a count of individual victims or confirmed consumer losses. They do not measure today’s risk for a particular account.

2. How can thieves alter a stolen check?

In check washing, thieves alter legitimate checks to change the payee name or amount.

The Postal Inspection Service describes chemical removal of ink as one method and notes that scammers may also use copiers or scanners to produce fake copies. Because methods and results vary, claims that a specific solvent always works—or that a particular ink is invulnerable—are not reliable.

Different changes require different questions for your bank. Was the payee changed, was the amount increased, was an endorsement forged, or was a counterfeit copy used? You do not need to diagnose the technical method yourself. Explain what you originally authorized and ask the bank to compare that with the check image and transaction details. Avoid handling a suspicious check as an experiment or trying to reproduce washing methods.

3. Which pens help protect checks from washing?

Use a dark gel-ink pen when writing a check.

The OCC lists black gel ink as highly resistant to check washing, but it is a precaution rather than a guarantee: criminals may use other alteration or copying methods. Fill in the payee and amount clearly, use the full available space on the amount line, and avoid leaving blank fields that could be completed by someone else. If you rarely need checks, consider a safer electronic payment method.

Do not rely on a brand name or a claim that any pen is “wash-proof.” The practical safeguards are to limit checks in the mail, monitor your account, and act quickly if a payment is missing or altered. OCC check-fraud guidance.

Writing technique matters as well as ink. The OCC’s older check-fraud prevention guide advises avoiding large blank spaces in number and amount lines. Complete the recipient and amount before giving a check to anyone. Keep unused checks and account records secure. Changing your pen does not address mail theft, copied check images, or information stolen from discarded account records, so combine precautions rather than treating one product as a complete solution.

4. Who may be responsible when a washed check clears?

Responsibility for an altered check depends on the facts, applicable state law, and the account relationship.

Do not assume that a single nationwide 30-day deadline guarantees reimbursement or determines liability. Review statements and transaction alerts regularly, and notify your bank or credit union as soon as you discover a problem. The CFPB advises customers whose checks were stolen and cashed to contact their financial institution right away, explain what happened, and ask about restoring the funds. CFPB guidance on stolen checks.

Deposit insurance is a separate subject: it protects eligible deposits if an insured bank fails, not a promise that an altered check will be reimbursed. Our guide to checking bank deposit insurance explains that distinction. For the disputed payment, ask your bank what rules and notice requirements apply to the actual transaction.

The CFPB distinguishes a changed amount from an endorsement forged on a stolen check. Its altered-check amount guidance says you may be able to have the difference restored, while remaining responsible for the original amount. If a check was processed as an electronic transfer, additional federal protections may apply; otherwise state-law protections may apply. Do not import credit-card or debit-card timelines into every paper-check dispute. Ask how the payment was processed and what information the bank needs to investigate.

5. What should you do if a check is washed?

Contact your bank or credit union promptly and report the specific check, the amount you expected, and the amount or payee shown in the transaction.

Ask the institution how to dispute it, whether to stop payment on any outstanding checks, and whether it recommends changing account details. Request a copy of the cleared check and keep notes, case numbers, and copies of correspondence. Your bank may ask for a written statement or other documents; requirements vary.

If mail theft may be involved, report it to the U.S. Postal Inspection Service and your local police. The Postal Inspection Service specifically advises affected people to report the incident to USPIS, local police, and their credit reporting bureau. Continue monitoring your account and follow up with the bank about its investigation. For broader recovery steps, see our guide to responding after a financial scam.

Make your first call factual and specific: “I wrote check [number] for [original amount] to [recipient]. My account now shows [what changed]. Please explain how to dispute it and protect other outstanding checks.” Do not guess at an offender’s identity or assume which documents are mandatory. Ask for a reference number, record when you made the report, and note the follow-up instructions. If the bank asks for documents, keep copies of what you submit.

1. Identify the original payment and the suspicious transaction.
2. Ask for the front and back of the paid check.
3. Ask whether other checks or the account need protection.
4. Follow the bank’s written dispute instructions.
5. Report suspected mail theft and keep your report details.

6. How can businesses prevent check washing fraud?

Businesses that issue checks can ask their bank about Positive Pay and related controls.

With conventional Positive Pay, the business provides issued-check details—commonly check number, amount, and date—for comparison against checks presented for payment. Payee Positive Pay may also compare payee information, depending on the bank’s service. Staff should review exception notices promptly and maintain clear procedures for approving and reconciling payments. Availability, matching fields, cut-off times, and fees vary by institution, so confirm details with the bank.

Positive Pay is a useful control, not a guarantee or a mandatory service. Businesses can also limit who may issue checks, reconcile accounts regularly, and use electronic payments where appropriate.

The OCC’s check-fraud guide describes Positive Pay as comparing checks presented for payment with information supplied by the customer. Ask what fields your service actually checks; do not assume payee matching is included. Find out who receives an exception notice, how a decision is submitted, and what happens if nobody responds by the bank’s deadline. Keep the issued-check records consistent with what you actually approved. Treat an unexpected exception as something to examine, not as proof that a payment is safe merely because the system accepted it.

7. Can you recover money after check washing?

Contact your bank promptly, provide the information it requests, and ask how to challenge the payment and what timelines apply to your account.

If you signed a check without filling in the recipient, tell your bank that as well. The CFPB’s stolen-check guidance says the usual protections generally do not apply to a signed blank check and recommends stopping payment if one is lost. Do not complete a dispute form as if every detail was filled in when that was not the case; the facts can change the outcome.

A bank’s investigation and the outcome depend on the circumstances and applicable law; reimbursement is not automatic. If you cannot resolve a complaint with your bank, you may submit a complaint to the appropriate regulator. The CFPB accepts complaints about many financial products and services; the OCC handles complaints about national banks and federal savings associations.

Keep copies of the check image, bank correspondence, and any police or mail-theft report. For broader guidance, see our resource on reporting financial fraud.

A regulator complaint is different from the initial bank dispute or a police report. Include a concise explanation of the problem, the steps you have already taken, and what resolution you are requesting. The OCC complaint instructions explain how to check whether the bank falls within its authority and say to contact the bank before filing. Neither filing a complaint nor contacting an agency guarantees repayment. Continue communicating with your bank about the original transaction and preserve its responses.

Defending Your Financial Accounts

When practical, use electronic payments instead of mailing a check. If you do mail one, use dark gel ink, place outgoing mail in a collection box before its last pickup or take it to a Post Office, and do not leave mail in a residential mailbox overnight. Retrieve incoming mail frequently and arrange for it to be held or collected when you are away.

When you are away from home, arrange for mail to be held at the Post Office or picked up by someone you trust. USPIS recommends this rather than allowing incoming mail to accumulate. Check the collection schedule before posting outgoing mail; a convenient drop-off location is not a guarantee against theft.

Turn on transaction alerts if your bank offers them and review account activity regularly. If a check is missing, altered, or paid to the wrong person, contact your financial institution promptly and report suspected mail theft to the Postal Inspection Service. For checking a financial provider before sending money, use our verification tool.