# Payment Account Validation

## Payment Account Validation Authentication Method

### Security and Authentication Requirements

The Payment Account Validation API uses mutual SSL authentication and channel encryption, which requires the caller to obtain a user ID and password as well as install a PKI certificate issued by Visa. Test credentials can be obtained online in the Project Console for sandbox testing. Production credentials will be supplied to you as part of the production on-boarding process. Contact [developer@visa.com](mailto:developer@visa.com) for more information or to begin the production on-boarding process.

#### Two-Way SSL

As one of the security protocols, Visa Developer sandbox secures its connections with clients by means of Two-Way SSL (Mutual Authentication) method. Refer to the link below to quickly learn about how to get credentials to start building with Two-Way SSL.

Visit the [Two-way SSL Guide](https://developer.visa.com/pages/working-with-visa-apis/two-way-ssl) to learn more.