Skip to main content Skip to footer site map

Fraud & Security

We’re there with tools and strategies to help you combat fraud. We help merchants recognize and prevent fraud before it happens, and arm them with tools and support to manage when it does. For Financial Institutions, help protect your cardmembers from fraud and insulate your revenue. Through our multi–layered fraud prevention tools and services.

  • For Merchants

    for merchants

  • For Financial Institutions

    Financial Institutions

  • card identification features

    Card Identification Features

    Identify the security features built right into every Discover card.
  • Card Identification Data

    Card Identification Data (CID)

    The three-digit CID provides an additional layer of security to ensure the card was in the possession of the cardmember at the time of purchase.
  • card present transaction

    Card Present Transactions

    Learn effective strategies to prevent fraud when you’ve got the card in hand.
  • address verification

    Address Verification Services (AVS)

    To limit fraud on card not present transactions, we require merchants to capture the cardmember’s address for verification.
  • card not present transaction

    Card Not Present Transactions

    Recognize suspicious behaviors and common risks for sales when the card is not present such as online or by telephone.
  • address change notification

    Address Change Notification (ACN)

    Minimizes the risk of account takeover fraud. Merchants requesting an AVS in the authorization message are sent an ACN. The ACN indicates the number of days since the last cardholder billing address change, if the change was within the last 45 days.
  • fraud prevention

    Fraud Prevention FAQ

    Get helpful answers to the most common questions about how you and your employees can recognize and prevent fraud.
  • card verification value

    Card Verification Value (CVV)

    A unique value encoded on the magnetic stripe by the issuer provides protection against counterfeit cards.
  • PCI Overview

    PCI Overview

    In order to help protect the integrity of cardholder data, Discover requires all merchants to remain PCI compliant.
  • code 10 suspicious situations

    Code 10: Suspicious Situations

    Merchants who become suspicious during a card present transaction can phone in a Code 10 authorization request, which alerts the issuer and protects the cardmember. Our automated authorization line will automatically connect the merchant to the appropriate issuer.
  • ID merchant level

    Identifying Your Merchant Level

    Find out what merchant level your business corresponds to and determine your compliance validation and reporting requirements.
  • 100 percent authorization

    100% Authorization Requirement

    We protect profits by requiring authorization on all transactions.
  • Determining Validation

    Determining Validation and Reporting Requirements

    Once you’ve determined your merchant level, it’s easy to find out your validation and reporting requirements.
  • stand-in functionality

    Stand-in Functionality

    Assists participating issuers with providing merchants authorizations when systems are down.
  • Performing PCI DSS

    Performing a PCI DSS Compliance Assessment

    Determining your compliance includes testing business facilities, system components, and verifying security of third party service providers.
  • Fraud Awareness

    Fraud Awareness & Alert Reporting

    Receive proactive warnings about high-risk authorization activity plus regular updates on fraud trends.
  • FirstTimePCI

    First-Time PCI Compliance Assessments

    If you’re performing a PCI DSS assessment for the first time, here are tools and resources to provide guidance and assistance.
  • tools to assist

    Tools to Assist with Assessments

    Access tools and resources to provide guidance and assistance for undergoing your PCI DSS assessment.
  • education training

    Education and Training

    Browse the educational and training materials we make available to help you understand the compliance assessment process and your place in it.
Please Note: JavaScript is not enabled in your web browser. In order to enjoy the full experience of the Discover Network website, please turn JavaScript on. If JavaScript is disabled, some of the functionality on our website will not work.