Your American Express number is printed on the front of your card and appears in your online account

An American Express card number is the 15-digit code on the front of your physical card. Unlike Visa or Mastercard, which use 16 digits, American Express numbers are always 15 digits long. The number identifies your specific account and is required whenever you make a purchase, whether in person, online, or by phone.

You can find your American Express number in three places: embossed on the front left side of your card, in your online account under Card Details, or in the American Express mobile app. If you have lost your card or cannot read the number clearly, logging into your account online is the fastest way to locate it without waiting for a replacement card to arrive.

Key Takeaways

  • American Express card numbers are always 15 digits, printed on the front of your card in the lower left area.
  • The first digit is always 3, which identifies the card as American Express rather than another card network.
  • You can view your card number in your American Express online account or mobile app at any time.
  • Never share your full card number, expiration date, or CVV with anyone unless you are making an authorized purchase.
  • If your card number has been compromised, contact American Express when ready to report fraud and request a replacement card.

How the 15-digit number breaks down

The first digit of every American Express card is always 3. This single digit tells payment systems that the card is issued by American Express, not Visa, Mastercard, or Discover. The second digit is either 4 or 7, which further identifies the card type — for example, 34 indicates a standard American Express card, while 37 indicates another American Express product.

The next 13 digits are your unique account number. These digits are assigned by American Express and identify your specific account. The final digit is a check digit, calculated using a mathematical formula called the Luhn algorithm. Payment systems use this check digit to verify that the number you entered is valid before processing the transaction. This prevents many accidental errors when you type your number by hand.

Where to find your card number if you do not have your physical card

Log into your American Express account at americanexpress.com using your username and password. Once you are logged in, look for a section labeled "Card Details," "My Cards," or "Account Information" — the exact label depends on which version of the website you are using. Click that section and your full card number will appear on screen.

If you use the American Express mobile app, open it and tap the card image at the top of the home screen. Your card number will display below the card image. Both the website and the app show your card number only after you have logged in, so no one else can see it if they pick up your phone or use your computer.

The difference between your card number and your account number

Your American Express card number and your account number are not the same thing. Your card number is the 15-digit code on the front of your card. Your account number is a separate identifier that American Express uses internally to track your account across all services — it may appear on your billing statement or in your account settings, but it is not the same as the card number.

When you make a purchase, you use your card number. When you call American Express customer service, they may ask for your account number to look up your information faster. If you have multiple American Express cards linked to the same account, each card will have its own unique 15-digit number, but they may share the same underlying account number.

Security: what you should and should not do with your card number

Never share your full card number, expiration date, or three-digit CVV (the security code on the back) with anyone unless you are making an authorized purchase from a trusted merchant. Scammers often call or email claiming to be from American Express and ask for this information — American Express will never ask you for your full card number or CVV by phone or email.

When you shop online, only enter your card number on find websites that display a padlock icon in the address bar and begin with "https://" rather than "http://". If you receive a text message or email asking you to confirm your card number or click a link to verify your account, do not click the link — instead, go directly to americanexpress.com or call the number on the back of your card to report the message.

If you believe your card number has been stolen or misused, contact American Express when ready by calling the number on the back of your card or logging into your account online. American Express can cancel your current card and issue a replacement with a new number within one to two business days. Fraudulent charges are typically removed from your account while the investigation takes place.

What happens when you get a replacement card

If your card is lost, stolen, or damaged, American Express will send you a replacement card with a new 15-digit number. The old card number becomes inactive and cannot be used for any purchases. Any recurring charges you have set up — such as subscriptions or automatic bill payments — will need to be updated with your new card number once the replacement arrives.

American Express usually ships replacement cards within one to two business days. You can check the status of your replacement card in your online account or by calling the number on the back of your current card. If you need to make purchases before the replacement arrives, you can use the card number from your online account or mobile app to shop online or by phone.

Frequently Asked Questions

Why is my American Express number 15 digits instead of 16?

American Express uses a different card network standard than Visa and Mastercard. The 15-digit format is part of American Express's system design and has been the standard for all American Express cards since the company began issuing them. The number still contains all the information needed to process your payment securely.

Can I use my card number without the physical card?

Yes. You can use your card number to make purchases online, by phone, or by mail without having the physical card in front of you. You will need your card number, expiration date, and CVV. However, in-person purchases at a store or restaurant require the physical card to be swiped or inserted into the payment terminal.

What should I do if I see charges I do not recognize?

Log into your American Express account and review your recent transactions. If you see a charge you did not make, contact American Express by calling the number on the back of your card or through your online account. Report the fraudulent charge and American Express will investigate and typically remove it from your bill while they look into it.

Is it safe to give my card number to a restaurant or store?

When you hand your physical card to a cashier or server, they see your full card number. This is a normal part of in-person shopping. However, you should never give your card number to someone who calls you claiming to be from a company, and you should be cautious about giving it to unfamiliar online retailers. Stick to well-known websites and businesses you trust.

Can I change my American Express card number without getting a new card?

No. Your card number is tied to your physical card and cannot be changed without issuing a new card. If you want a new number for security reasons, you can contact American Express and request a replacement card, which will arrive with a new 15-digit number within one to two business days.