Fraud Prevention Best Practices

Gain helpful tips for identifying and preventing fraud

Suspect fraud?

Call 1-800-347-1111 | Authorization Code—10

Card-Present Transactions

How to Detect a Counterfeit or Altered Discover®Card

A card may be fraudulent if:

  • The last four printed or embossed numbers are different from the last four printed on the transaction receipt
  • The standard security features appear altered or damaged, or don't match the examples provided

Standard Security Features Common to Discover Cards

3D Holograms
3D Hologram

Some cards display a three-dimensional hologram on the card front with a globe pierced by an arrow.

Holograpic Magnetic Stripe
Holograpic Magnetic Stripe

Many cards display a three-dimensional holographic magnetic stripe, which, when tilted, shifts color and appears to move.

Card Identification Data (CID)
Card Identification Data (CID)

A three-digit CID is printed in a separate box to the right of the signature panel on the card back. It ensures the cardholder possesses the card at the time of purchase.

The cardholder may choose to verify the CID during any authorization request for keyed or swiped transactions.

Discover Acceptance Mark
Discover Acceptance Mark

The Discover Acceptance Mark will appear on the front or back of the card.

Tamper-Evident Signature Panel
Tamper-Evident Signature Panel

"DISCOVER" or "DISCOVER NETWORK" appears on a tamper-evident signature panel. Some cards contain an ultraviolet image that repeats the word "DISCOVER" in the signature panel.

  • Does the original signature panel show signs of tampering?
  • Is the word “VOID” exposed by an erasure?
  • Is the printing of the word(s) “DISCOVER” or “DISCOVER NETWORK” in the signature panel unclear or not tilted at the standard 20-degree angle?
“Valid Thru” Date
“Valid Thru” Date

"Valid Thru" indicates the last month in which the card is valid.

Stylized D
Stylized "D"

On embossed cards, a security character appears as a stylized "D." A missing "D" on an embossed card may help you detect a counterfeit or altered Discover card.

On unembossed cards, no stylized "D" will appear.

Business Name
Business Name

A business name may be embossed below the cardholder name.

Card Numbers
Card Numbers

All Discover card numbers start with 6. On embossed cards, the card number should be uniform in size and spacing. On unembossed cards, the card number and expiration date are printed flat on the front.

Ultraviolet Effect
Ultraviolet Effect

Under an ultraviolet light, "DISCOVER" or "DISCOVER NETWORK" will appear on the card.

Card-Not-Present Transactions

Verify Information Now

To obtain an authorization or address verification, or to question the validity of a Discover card, call the Discover® Global Network Authorization Center at 1-800-347-1111.

Tips to Reduce Chargebacks and Risks


  • Include your common DBA and customer service number on the customer's transaction receipt and the billing statement
  • Obtain an authorization for duplicate charges, or installment plans, unless otherwise stated
  • Get notified of confirmed fraudulent transactions and recalled goods by enrolling in our free fraud prevention solution, Fraud Alerts

Before the Transaction

  • Clearly communicate all delivery charges, restocking fees, or other fees
  • Explain return policies and offer documentation of these policies with each sale

During the Transaction

  • Verify the customer's billing address electronically, by our automated phone system, or by an Address Verification System (AVS)
  • Request and validate the CID (the three-digit code on the back of the card in the signature panel)
    • The CID can be submitted in the electronic authorization request or can be used when calling our authorization center

Note: All declined authorizations are final

After the Transaction

  • Verify the customer's name, full billing address, email address, and phone number by enrolling in our free fraud prevention solution, Verify+
  • Get a signature for each delivery and keep all delivery records
  • Document efforts to satisfy the customer when working on a chargeback
  • Respond to all chargebacks, even the small ones
  • Refund sales on the same card account used for purchase

Related Resources

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