What biometric authentication is
Biometric authentication checks whether a person matches an enrolled physical or behavioral trait, such as a fingerprint, face, iris or voice. A device, payment card or service compares the new scan with an enrolled reference, then returns a match result. The method verifies identity, not whether a purchase is legitimate.
The biometric information is handled differently across systems. In one card-on-card design described by Mastercard, the fingerprint template stays on the card and the issuer receives the match result with the authorization request. In an online card feature, biometrics can instead be managed through the customer's device and app.
Biometrics verify the person, but they do not set your processing rate or guarantee a payment is fraud-free.
Where you may encounter it
A customer might use a fingerprint or face scan to unlock an account, approve access in an app or confirm identity during an online checkout. Biometrics can also be one way a cardholder completes a challenge within 3-D Secure. The biometric scan is a verification method; 3-D Secure is the separate protocol used to authenticate an online card transaction.
Biometric authentication is broader than biometric payments. It can secure logins that happen before a customer pays, while biometric payments specifically use a biometric as part of the payment experience. A fingerprint-enabled payment card is one example: the customer scans a finger on the card, then taps or inserts it at the terminal.
What it means for your costs and risk
The available card-acceptance guidance does not specify a biometric-authentication fee, and the biometric card described there does not change interchange. Do not treat a biometric feature as a new card-processing fee unless a specific charge appears in your agreement or statement. There is no standard biometric line item identified here.
A biometric match is not a guarantee that a transaction is authorized or free from fraud. In the card example, the issuer uses the match result as part of its approval decision, and a failed match leads to another cardholder verification method such as a PIN or signature. Biometrics alone do not establish a separate chargeback-liability rule.
What you can actually change
You do not set the biometric method or its underlying match rules, but you control the customer experience and the charges your business accepts. Keep the fallback path clear so a failed scan does not leave a customer unable to complete checkout.
- Keep an alternative authentication method available, such as an OTP, PIN or signature where the payment flow supports it.
- For an online checkout, explain how customers can complete authentication if their device does not support biometrics.
- Review any new statement or agreement charge separately; biometric authentication is not itself a standard processing-fee category.
- Treat a biometric step and 3-D Secure as distinct controls when reviewing online transaction and dispute processes.
- Test the fallback. Run a checkout test with biometrics unavailable and confirm customers can still authenticate and pay.
- Separate the controls. Document whether your online flow uses biometrics, 3-D Secure or both, since they serve different roles.
- Check new charges. Compare any new authentication-related statement line with your agreement before treating it as a standard card fee.
Frequently asked questions
Is biometric authentication the same as biometric payments?
No. Biometric authentication is a way to verify identity, including for logins and online payment authentication. Biometric payments use that identity check as part of the payment experience, such as a cardholder matching a fingerprint on a biometric payment card.
Does biometric authentication reduce card-processing fees?
There is no standard biometric-authentication fee identified in the card-acceptance guidance, and the biometric card example leaves interchange unchanged. A biometric feature does not automatically lower your processing rate or create a new fee.
Does a fingerprint or face scan shift chargeback liability?
A biometric match alone does not establish a chargeback-liability shift. In a biometric card example, the issuer uses the match result in its authorization decision, while the applicable transaction and dispute rules remain separate.