# Redirect URLs
source: https://developer.mastercard.com/open-banking-connect/documentation/redirect-urls/index.md

### TPP Redirect URLs {#tpp-redirect-urls}

The `tppRedirectURI` is used in open banking authentication flows where an ASPSP needs to redirect the PSU after a successful authentication.

#### Production requirement {#production-requirement}

In Production, the redirect url must be enrolled with each ASPSP along with the TPP's certificate.

#### ASPSPs use of TPP Redirect URLs {#aspsps-use-of-tpp-redirect-urls}

The ASPSP uses the redirect URI to send a code that is required to complete authentication for each PSU. This authorization code is used by the TPP to redeem a payment (see [Payment Credit Transfer Initiation](https://developer.mastercard.com/open-banking-connect/documentation/pisfeatures/payment-credit-transfer-initiation-request/index.md) or request consent to retrieve account information (see [Exchange the PSU Authorization for Access Consent](https://developer.mastercard.com/open-banking-connect/documentation/aisfeatures/exchange-psu-consent/index.md)). Most ASPSPs will not send an authorization code to an unregistered TPP redirect url, as it is used to verify the identity of a TPP and is linked to their license. In the case where a TPP wants to change their redirect url in production it will require a new registration with the bank before it can be used to process requests from the bank.

#### Multiple Redirect URLs {#multiple-redirect-urls}

Most ASPSPs will support the addition of multiple redirect urls, but some banks will only support the addition of one redirect url per TPP.

#### Sandbox TPP Redirect URLs {#sandbox-tpp-redirect-urls}

In Sandbox, Mastercard Open Banking Connect allows TPPs to test with different dynamic redirect urls. This enables TPPs to test with different urls and verify flows using our available sandbox ASPSPs. If TPPs intend to submit requests to ASPSP sandboxes using their own redirect URLs, they need to contact their Mastercard client representative to ensure that the TPP redirect URL is added to the Mastercard TPP (and is whitelisted).  

Before moving to Production, it is important to note that the preferred redirect url to be used must be shared with Mastercard so that we can begin the onboarding process with the Production banks.