Check Washing Fraud
Criminals intercept mailed checks, chemically erase the ink, and rewrite the payee name and amount before cashing or depositing them fraudulently.
Last reviewed: 1 June 2026
What this scam is
Check washing fraud is a form of financial document tampering in which a criminal obtains a legitimately issued check — typically by stealing it from a mailbox or post box before delivery — and uses household chemicals to erase the ink. Once the original writing has been removed, the fraudster rewrites the check with a new payee name, a larger amount, or both, and then cashes or deposits it.
The process is surprisingly accessible to fraudsters: nail polish remover, acetone, bleach, and similar chemicals found in most homes can remove standard ballpoint pen ink from check paper without visibly damaging the document. Gel pens using certain inks are far more resistant to chemical removal, which is why financial advisors often recommend their use for completing checks.
The scheme is most common in regions where paper checks remain in widespread use for paying bills, rent, and personal transactions. Victims typically discover the fraud when the legitimate payee contacts them asking why a payment has not arrived, or when they notice an unexpected debit on their bank statement that does not match the amount they wrote on the check.
Because a washed check bears the account holder's genuine signature and account details, reversing the fraudulent transaction can take weeks and requires the bank to investigate the alteration claim. Victims bear the burden of proof and may temporarily be held responsible for the altered amount.
How it works
The process begins with check interception. Fraudsters target unsecured outdoor mailboxes, post boxes awaiting collection, and mail that has already been delivered but not yet retrieved. They look for envelopes that feel like they contain a check — standard letter-sized envelopes with hand-written addresses and no window are a common indicator.
Once a check is obtained, the criminal applies a chemical solution to erase the payee name and the dollar or pound amount written in ink. With the check paper otherwise intact — including the signature, routing number, and account number — the fraudster then uses a new pen to write in a different payee name (often their own alias or an accomplice's) and a higher amount.
The altered check is then deposited or cashed, usually through a different bank, mobile deposit, or an accomplice's account. Because the check appears genuine — it has a real signature and real account details — it often clears before the fraud is detected.
The victim does not discover the theft until they review their bank statement and notice an amount they do not recognise, or until the original payee contacts them about a missed payment. By this point, the funds may already have been withdrawn from the fraudster's account.
Why this scam works
Check washing works because the physical check appears entirely genuine after alteration. The signature is authentic, the paper is real, and the account information is accurate. Banks process checks based on the document in front of them, and staff do not typically scrutinise every check for signs of chemical alteration.
Outdoor mailboxes provide easy, low-risk access for thieves, particularly in rural areas or properties where mail is left unattended for extended periods. The time between posting a check and the recipient depositing it can be several days — giving a fraudster a wide window to intercept, alter, and cash the item before anyone notices.
Common red flags
- Bank statement shows a check cleared for a different amount than you wrote
- Check is payable to a name you do not recognise
- Payee contacts you saying your check payment never arrived
- Unusual chemical smell or faint discolouration on the check body when you review it
- Check clears much faster or much later than expected
- Bank statement shows your account number debited by an amount you do not recall authorising
- A check you posted was not cashed by the intended payee but has still cleared your account
Sanitized example messages
Illustrative, sanitized examples. Personal details are replaced with placeholders such as [phone number] and [fake link].
Hi [Name], I just wanted to check — I haven't received the payment you said you sent. Could you confirm when it was posted?
Dear Account Holder: We have received a dispute on check number [XXXX]. Please contact our fraud team at [number] to review the transaction.
Your payment of [amount] to [payee name] has been processed. If you did not authorise this amount, please contact us immediately.
We are writing to advise that a check drawn on your account has been flagged for review. A member of our fraud team will contact you within [X] business days.
Check [number] for [amount] payable to [name] cleared on [date]. If you have any questions about this transaction, log in to your account or call [number].
Common variations
- Counterfeit check creation: fraudster uses the routing and account number from a stolen check to print entirely new forged checks
- Partial washing: only the amount is altered while the payee remains unchanged, making the fraud harder to detect
- Business check targeting: company payroll or supplier checks are targeted because they tend to be for larger amounts
- Mobile deposit exploitation: altered check is deposited via mobile app before the original theft is reported
How to verify before you act
Use a gel pen when writing checks — gel ink bonds more deeply with paper fibres and is significantly more resistant to chemical washing. Avoid ballpoint pens for completing check amounts and payee names.
Consider switching to electronic payments for recurring bills and rent. If you must send a check, use a tracked or signed-for postal service, drop it directly into a post office collection box rather than a street or outdoor mailbox, and follow up with the payee to confirm receipt within a few days of sending.
Monitor your bank statements carefully. If you notice a check transaction for an amount different from what you wrote, or to a payee you do not recognise, contact your bank's fraud team immediately and ask them to investigate the check for alteration.
Payment methods used
- Cryptocurrency
- Bank/wire transfer
- Gift cards
- Money transfer services
- Payment apps to 'friends & family'
Who is usually targeted
- Anyone who mails paper checks for bill payments or rent
- Small business owners paying suppliers by check
- Older adults who use checks regularly
- Residents in areas with unsecured outdoor mailboxes
What to do immediately
- Contact your bank's fraud line immediately if you spot a check transaction for an unrecognised amount or payee
- Request the bank preserve the physical check for forensic examination
- Ask the bank to reverse the transaction and initiate a forgery or alteration claim
- File a report with your national postal authority if you suspect the check was stolen in transit
- Report the fraud to your national cybercrime or financial crime reporting body
- Notify the legitimate payee that you will need to reissue payment
- Review all recent check transactions to identify whether more than one check has been tampered with
How to prevent it
- Use a gel pen when writing checks — gel ink is far more resistant to chemical removal than ballpoint ink
- Consider switching to electronic bank transfers, which cannot be altered after sending
- Mail checks at a post office counter or directly into a locked collection box rather than an outdoor mailbox
- Follow up with the payee to confirm receipt within three to five business days of mailing
- Review your bank statements weekly and query any check transaction that does not match your records
- If your mailbox is outdoors and unsecured, upgrade to a locking model or switch to a PO box
- For large payments, consider using certified or tracked mail with a return receipt
Evidence to preserve
- Your check register or record showing the original payee name and amount
- Bank statement showing the altered transaction details
- Any communication from the intended payee confirming non-receipt
- Envelope photos or postmark details if available
- Bank's copy of the physical check once your fraud claim is filed
- Any correspondence from the bank relating to the fraud review
Where to report it
- Action Fraud (UK) — UK national fraud & cybercrime reporting centre
- FTC ReportFraud (US) — US Federal Trade Commission fraud reports
- FBI IC3 (US) — US Internet Crime Complaint Center
- Scamwatch (Australia) — Australian competition & consumer reporting
- Your bank's fraud line — Use the number on the back of your card or in your banking app — never a number the caller gives you
Always verify reporting routes and emergency contacts on the official government or agency website for your country.
Frequently asked questions
Is the bank responsible for covering the loss if my check was washed?
Responsibility varies by country and bank policy. In the US, the Uniform Commercial Code generally requires banks to cover losses from altered checks if the customer did not contribute to the loss through negligence, but the process requires filing a formal forgery claim and can take weeks. In the UK, banks investigate claims case by case. Document everything carefully, act quickly, and follow your bank's formal dispute process. Do not simply accept a denial if you have evidence the check was altered.
How can I tell if a check I received has been washed?
Inspect the check under a bright light or UV lamp. Look for uneven patches, faded areas, smearing around the payee name or amount, or slight colour differences where ink has been reapplied. The signature area may appear undisturbed while other areas look subtly different. If you suspect a check you received has been altered, do not deposit it — contact the issuing bank to verify the details directly before cashing.