Write your account number and "For Mobile Deposit Only"

The back of a check for mobile deposit needs two things: your account number and the phrase "For Mobile Deposit Only." Write your account number in the top left corner of the back, then write "For Mobile Deposit Only" in the center or slightly below. This tells the bank that the check is meant to be deposited through their app, not processed through the mail or at a teller window.

The reason banks require this language is security. A check marked "For Mobile Deposit Only" cannot be cashed in person or deposited at an ATM. If someone finds or steals the check, they cannot walk into a branch and cash it. The restriction is enforced by the bank's system — when a teller or ATM scans the back, it will reject the deposit if the proper language is missing.

Do not sign the back of the check. Your signature on the front is enough. Some people worry that leaving the back unsigned makes the check invalid, but for mobile deposit it actually makes it safer — an unsigned back means someone else cannot forge your name and try to cash it in person.

Key Takeaways

  • Write your account number in the top left corner of the back of the check.
  • Write "For Mobile Deposit Only" in the center of the back to restrict how the check can be deposited.
  • Do not sign the back of the check when depositing through a mobile app.
  • The "For Mobile Deposit Only" restriction prevents the check from being cashed in person or at an ATM if it is lost or stolen.
  • Different banks may have slightly different requirements, so check your bank's app or website for any additional instructions.

Why banks require the account number on the back

Your account number on the back tells the bank's system which account to deposit the money into. When you photograph the check with your phone, the app reads the routing number and check number from the front, but it needs your account number to know where the funds should land. Without it, the deposit may be rejected or delayed while the bank tries to match the check to your account manually.

If you forget to write your account number, the deposit will usually fail immediately — the app will tell you the back of the check is unreadable or incomplete. You can then write the number and try again. Some banks allow you to type your account number into the app instead of writing it on the check, so check your bank's specific process before you deposit.

How to photograph the check correctly

After you write the required information on the back, photograph both sides of the check in good lighting. The front should show the payee line (the name the check is written to), the amount, the date, and the signature. The back should show your account number and "For Mobile Deposit Only" clearly enough that the app can read them.

Most bank apps will tell you if the image is too blurry or if required information is missing. If you get an error, retake the photo in brighter light or at a different angle. Do not deposit the same check twice — once the app accepts it, the check is marked as deposited in the bank's system, and a second deposit will be rejected or flagged as fraud.

What happens after you submit the deposit

After you photograph and submit the check through the app, the bank sends it to a processing center where it is scanned and verified. The funds are usually available in your account within one to two business days, though some banks make the money available immediately for checks under a certain amount. Your bank's app will show you the status of the deposit — pending, processed, or rejected.

Keep the physical check until the deposit shows as complete in your account. Do not throw it away or deposit it again. Once the bank has processed it, you can destroy it by shredding or tearing it up. If the deposit is rejected, the app will tell you why — usually because the image was unclear, the account number was wrong, or the check was already deposited.

Common mistakes that cause mobile deposits to fail

The most common error is writing the account number illegibly or in the wrong spot. Write it large enough that a camera can read it, and put it in the top left corner where the app expects to find it. Another mistake is forgetting "For Mobile Deposit Only" entirely — the app will reject the deposit if this phrase is missing.

Some people write too much on the back of the check, which can confuse the app's image recognition. Stick to your account number and the required phrase. Do not add notes, dates, or other information. If you need to communicate something to the bank, use the app's message feature or call customer service instead.

Differences between banks

Most major banks — Chase, Bank of America, Wells Fargo, and others — follow the same basic requirements: account number and "For Mobile Deposit Only." However, some smaller banks or credit unions may have different rules. Before you deposit, open your bank's app and look at the mobile deposit instructions. They will tell you exactly what to write and where.

A few banks allow you to skip writing your account number on the check if you type it into the app instead. Others require it on the check itself. Your bank's app will guide you through the process step by step, so follow those instructions rather than guessing.

What to do if the deposit is rejected

If the app rejects your deposit, read the error message carefully. It will usually tell you whether the problem is the image quality, missing information, or something else. The most common fixes are retaking the photo in better light, rewriting your account number more clearly, or making sure "For Mobile Deposit Only" is visible.

If the app keeps rejecting the deposit and you cannot figure out why, take the check to a branch in person or call your bank's customer service line. A teller can deposit it for you and explain what went wrong with the mobile deposit. Do not attempt to deposit the same check multiple times through the app, as this can trigger fraud alerts.

Frequently Asked Questions

Can I use a pen or does it have to be a specific type of ink?

Any pen works — ballpoint, gel, or marker. The app just needs to read the text, so use whatever you have on hand. Black or blue ink is clearest for the camera to read, but other colors usually work too.

What if I already signed the back of the check before I realized I shouldn't?

It is still fine to deposit. The signature on the back does not invalidate the check or cause the mobile deposit to fail. The "For Mobile Deposit Only" restriction still applies, and the check cannot be cashed in person. Just make sure your account number and the required phrase are also written on the back.

Do I need to write anything on the front of the check?

No. The front of the check should already have the payee name, amount, date, and your signature from when the check was written to you. Do not write anything else on the front — it can interfere with the app's ability to read the check information.

What if the check is made out to a business, not me personally?

You cannot deposit a check made out to someone else into your personal account, even with mobile deposit. The name on the check must match the account holder. If the check is made out to your business, you need to deposit it into a business account. Contact your bank if you are unsure whether you can deposit a particular check.

Can I take a screenshot of the check instead of photographing it?

No. The bank app requires you to use your phone's camera to photograph the check in real time. Screenshots of images you took earlier will not work. The app needs to verify that you are depositing the actual physical check, not a copy or image file.