# Source: https://docs.stripe.com/disputes/prevention/verification.md

# Card verification checks

Learn how to make use of card verification checks to protect against disputes and fraud.

When a card payment is submitted to a *card network* (A network that processes the transactions of a particular card brand. It might be an intermediary in front of an issuing bank as with Visa or Mastercard, or a standalone entity as with American Express) for authorization, Stripe provides the CVC, postal code, and billing street address for them to verify (if you collected these from the customer in your checkout flow). The card issuer checks this against the information they have on file for the cardholder. If the provided information doesn’t match, the verification check fails. A failed CVC or postal code check can indicate the payment is fraudulent, so review it carefully before fulfilling the order.

Each [Charge](https://docs.stripe.com/api.md#charge_object) object includes the [verification response](https://docs.stripe.com/api.md#create_charge-verification-responses) as part of its `source` attribute. You can also find the verification results in the [Dashboard](https://dashboard.stripe.com/test/payments) when viewing a payment.

If no information is collected, the card issuer can’t perform a verification check. Collect the CVC, postal code, and billing address for every payment to avoid this issue. The results of verification checks help improve the detection of fraudulent activity.

## Card verification code check (CVC) 

The CVC (or CVV) is the three- or four-digit number printed directly on a card that only cardholders in physical possession of the card should have access to. When you require the CVC value with a card payment method (during payment or when attaching the payment method to a customer’s profile), the card issuer verifies the value during transaction authorization.

[Radar](https://docs.stripe.com/radar.md) allows you to block payments that fail the card issuer verification in various situations by enabling a [rule](https://docs.stripe.com/radar/rules.md#built-in-rules) through the [Dashboard](https://dashboard.stripe.com/test/radar/rules). This doesn’t affect payments where the CVC check couldn’t be performed or is unavailable. For example, *wallets* (A digital wallet is a contactless payment method that stores payment options, such as credit and debit cards, allowing customers to use a smart device to make a purchase) like Apple Pay or *off-session* (A payment is described as off-session if it occurs without the direct involvement of the customer, using previously-collected payment information) payments don’t require it.

Businesses can’t store the CVC number, so fraudsters are unlikely to obtain the CVC through a computer breach, making CVC verification an effective fraud prevention tool. However, CVC verification doesn’t protect against the physical theft of a card, nor computers or websites with poor security.

## Address verification (AVS) 

When you require the postal code and the billing street address with a card payment method (during payment or when attaching the payment method to a customer’s profile), the card issuer performs an AVS check to verify that they match the billing address on file.

*Radar* (Stripe Radar helps detect and block fraud for any type of business using machine learning that trains on data across millions of global companies. It’s built into Stripe and requires no additional setup to get started) allows you to block payments that fail the postal code (AVS) verification in various situations by enabling a [rule](https://docs.stripe.com/radar/rules.md#built-in-rules) in the [Dashboard](https://dashboard.stripe.com/test/radar/rules). AVS checks can fail for legitimate payments. For example, a customer who enters their address incorrectly or moves without notifying their card issuer might see payments where the address check fails.

Support for AVS checks varies by country and card issuer. For example, certain countries don’t use a postal code, and some card issuers don’t support street address verification. Most cards issued in the United States, Canada, and the United Kingdom support street address verification.

## See also

- [Best Practices for Preventing Fraud](https://docs.stripe.com/disputes/prevention/best-practices.md)
- [Types of Fraud](https://docs.stripe.com/disputes/prevention/fraud-types.md)
- [Identifying Fraud](https://docs.stripe.com/disputes/prevention/identifying-fraud.md)