Payment teams should pair stronger authentication with risk-based controls that match transaction value and channel sensitivity. Passkeys, biometrics, and other passwordless methods reduce reliance on reusable credentials, but they should be deployed with sound fallback handling, device binding, and fraud monitoring. The goal is to improve trust without creating new abuse paths across wallets, open banking, and online payment flows.
Strengthening authentication without slowing payment conversion
As payment journeys move into mobile wallets, open banking, and passwordless sign-in, the authentication problem changes from “is the password correct?” to “is this user, device, session, and transaction relationship credible enough to approve?” That shift matters because payment fraud often exploits weak step-up decisions, not just weak login methods. Teams need to treat authentication as part of the payment control stack, not as a standalone identity feature. The NIST SP 800-53 Rev 5 Security and Privacy Controls framework is useful here because it ties authentication, access enforcement, logging, and monitoring into one operational view rather than treating them as separate concerns. In practice, many payment teams discover the weakness only after a frictionless login path has already become the easiest route for account takeover or authorised-push-payment abuse.
Strong authentication in payments should be judged by whether it reduces fraud without blocking legitimate high-value activity. That means the control design has to reflect channel risk, transaction amount, payee trust, and device confidence. Passwordless methods can lower credential theft exposure, but they do not eliminate phishing, session theft, social engineering, or misuse of recovery flows. For that reason, the security question is not which method sounds modern, but whether the chosen method produces reliable assurance at the moment a payment decision is made.
How mobile wallets, open banking, and passwordless flows actually change the control model
In payment environments, authentication is no longer a single gate at login. It becomes a sequence of trust decisions across enrolment, device registration, step-up, payment approval, and recovery. Mobile wallets often shift trust to the handset and its secure element or platform authenticator. Open banking shifts trust to consent, API-bound sessions, and redirected or decoupled authentication. Passwordless access reduces dependence on shared secrets, but it also increases the importance of device provenance, recovery integrity, and session protection.
Teams should design the control model around transaction context. A low-value, familiar merchant payment may only require baseline authentication, while a new payee, unusual device, or high-value transfer should trigger stronger verification. Biometrics can improve usability, but they are best treated as local user verification, not as proof that a transaction is intrinsically low risk. The real assurance comes from combining the authenticator with binding to the device, application, and transaction details.
- Use risk-based step-up so the strongest checks are reserved for higher-risk transactions.
- Bind wallet or app access to managed device characteristics where feasible, especially for higher-value channels.
- Protect enrolment and recovery with the same care as live authentication, because abuse often shifts there when passwords disappear.
- Log authentication strength, device context, and payment outcome together so fraud patterns can be investigated coherently.
Passwordless programmes also need clear fallback rules. If the fallback is an SMS code, weak helpdesk reset, or a broadly reusable recovery channel, the overall assurance drops back toward the weakest path. The guidance breaks down when teams modernise the front end of authentication but leave enrolment, recovery, and exception handling materially weaker than the primary flow.
Where the edge cases and trade-offs show up first
Tighter authentication often increases user friction and operational overhead, so teams have to balance fraud reduction against conversion loss and support burden. That trade-off becomes most visible when payments cross borders, when devices are shared, or when customers frequently change phones. In those situations, a technically strong method can still perform poorly if recovery is clumsy or if step-up triggers are too aggressive.
There is also a genuine consensus gap in the market around how much biometric assurance should be relied on for payment approval. Good practice is to treat biometrics as one signal within a broader decision, not as a universal proof of identity. Likewise, open banking ecosystems may rely on different authentication and consent patterns depending on the bank, region, and scheme rules, so teams should avoid assuming one flow will fit all payment types.
For high-risk payments, the key edge case is not the normal checkout journey but the exception path: account recovery, new-device enrolment, and assisted support. Those are the places where attackers look for weaker controls, and where legitimate customers most often experience hidden breakage.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK address the attack and risk surface, while NIST CSF 2.0, CIS Controls v8 and NIST SP 800-63 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | PR.AA-01 — Identity Management, Authentication, and Access Control | Payment authentication relies on assurance across users, devices, and sessions. |
| Recommendation — Apply PR.AA-01 to enforce stronger authentication and access decisions for higher-risk payment actions. | ||
| CIS Controls v8 | 5.1 — Establish and Maintain an Inventory of Accounts | Payment auth strength depends on knowing which accounts and recovery paths exist. |
| 6.3 — Require MFA for Externally-Exposed Applications | Wallets and payment portals are exposed channels where stronger login assurance is essential. | |
| Recommendation — Maintain a current account inventory so payment authentication and recovery paths stay controlled. Require MFA or equivalent strong authentication on externally exposed payment interfaces. | ||
| MITRE ATT&CK | T1110 — Brute Force | Reusable credentials and weak fallback paths are common payment access abuse paths. |
| Recommendation — Monitor for automated authentication abuse and harden fallback paths against brute-force attempts. | ||
| NIST SP 800-63 | IAL2 — Identity Assurance Level 2 | Higher-risk payment enrolment and recovery need stronger identity proofing assurance. |
| Recommendation — Use IAL2 where payment enrolment or recovery requires stronger identity proofing. | ||
Practitioner Guidance
What to prioritise: Strengthen the weakest trust transition first, which is usually enrolment or recovery rather than the primary sign-in screen. If those paths are weaker than the new passwordless flow, the overall control still fails at the point attackers target most.
Decision rule: Treat authentication as sufficient only when it is paired with device confidence and transaction context. If either the device or the payment context is unknown, require step-up before approval.
What to verify: Confirm that fallback methods, customer support actions, and reset flows are held to the same assurance standard as the main journey. A passwordless programme is only as strong as its exception handling.
What practitioners underestimate: Fraud teams often focus on login strength and miss that many payment losses are driven by abuse of consent, recovery, or session continuity. The practical test is whether the team can explain why a specific transaction should be trusted, not just why a user passed an authentication screen.
Practitioner takeaway: The best payment authentication strategy is contextual, not absolute; it should raise assurance only where the transaction risk justifies it and keep recovery from becoming the easiest attack path.
Related resources from NHI Mgmt Group
- Should teams prefer passwordless authentication for regulated payment flows?
- How should security teams govern passwordless authentication for enterprise access?
- How should security teams implement passwordless authentication without increasing access risk?
- What should IAM teams review when moving toward passwordless access?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 9, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
