# Token Authentication
source: https://developer.mastercard.com/mastercard-checkout-solutions/documentation/token-authentication/index.md

Mastercard's Token Authentication Service (TAS) enables participating merchants to perform seamless and secure cardholder authentication during Secure Card on File and Click to Pay transactions. [Learn more](https://developer.mastercard.com/product/token-authentication-service/) about the key benefits of TAS.

Cardholders can create a payment passkey with Mastercard and use the payment passkey to authenticate digital transactions. The cardholder only needs to create the passkey once and use it at any participating merchant.

TAS is an implementation of the [Token Authentication Framework Guide](https://trc-techresource.mastercard.com/r/bundle/m_mc_taf_g_en-us/page/d/en-US/kof1745837091084.html) published on Mastercard Connect, and can be used in all markets where TAF is available.

Integrators that do not support TAS can continue to request cardholder authentication through the Mastercard Identity Check program (EMV 3-D Secure) outside of TAS, or alternative authentication solutions that are qualified by Mastercard under TAF.

For details on program eligibility, participant requirements, and authentication standards, refer to the [TAS Product Guide](https://techdocs.mastercard.com/bundle/m_TAS_en-us).
Note: Contact a [Mastercard representative](https://developer.mastercard.com/mastercard-checkout-solutions/documentation/support/index.md#get-help) to check the regional availability for TAF.

### Token Authentication {#token-authentication}

**for Click to Pay**   

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[Learn More](https://developer.mastercard.com/mastercard-checkout-solutions/documentation/token-authentication/click-to-pay/use-case1/index.md)

### Token Authentication {#token-authentication}

**for Secure Card on File**   

<br />


[Learn More](https://developer.mastercard.com/mastercard-checkout-solutions/documentation/token-authentication/secure-card-on-file/by-mastercard/use-case1/index.md)