Both are software-based second factors, but push notifications reduce user effort by replacing code entry with a simple tap to approve a login. Time-based one-time passwords require the user to read and type a short-lived code, which creates more friction for sight, motor, and cognitive impairments. Push is usually easier, while TOTP can still be practical when broader device support is needed.
Push approvals and TOTP both work as second factors, but the accessibility burden is different
For accessibility, the core difference is interaction cost. Push approval usually asks for one low-effort action after the user receives a prompt, while TOTP asks the user to locate a code, read it correctly, and type it before it expires. That extra reading and typing burden is what most often makes TOTP harder for users with visual, motor, or cognitive impairments.
Push is therefore generally the more usable pattern when the goal is to reduce friction without removing a second factor. TOTP remains useful when organisations need a broadly supported option that works across many devices and authenticators, but the accessibility trade-off is real and should be treated as a design choice, not a minor implementation detail.
Why the user experience changes so much
The accessibility gap is not just about convenience. Push notifications reduce the number of steps and the precision required from the user, which helps when screen reading, fine motor control, or short-term memory are part of the challenge. TOTP introduces more opportunities for error, especially when users must switch apps, remember where the code lives, and enter it before it expires.
That difference matters most in high-frequency login flows, recovery scenarios, and environments where users are already under time pressure. A second factor that is technically strong but operationally hard to use often produces more support calls, more failed sign-ins, and more workarounds, which can undermine real-world security adoption.
For a deeper identity-control view of this trade-off, NIST SP 800-63 Digital Identity Guidelines is the most relevant external reference because it frames authenticator choice around assurance and usability, not just technical presence.
When push is the better accessibility choice, and when TOTP still makes sense
Push tends to be the better default when the user population includes people who benefit from simpler interaction and when the organisation can support secure approval flows. It is especially useful when the authenticator can present context, such as location or login details, so the user is not approving blindly. That said, push is not automatically superior in every deployment, because notification delivery, device dependency, and prompt fatigue can affect reliability.
TOTP is often the more portable backup when users need an authenticator that works without push infrastructure or vendor-specific support. It can also be a practical option for users who prefer a code-based method and do not mind the extra effort. In accessibility terms, though, the question is whether the user can complete the flow consistently, not whether the method is familiar to the organisation.
From an operational control perspective, the safest approach is to offer more than one method where policy allows, then make sure the accessible path is available without forcing users into a less usable fallback.
Risk and Threat Considerations
Accessibility trade-offs can become security trade-offs when a method is hard to use. If a login factor is cumbersome, users are more likely to delay sign-in, abandon enrollment, rely on help desk exceptions, or choose weaker recovery paths, all of which can increase exposure. Push also carries approval-fatigue and prompt-spam risk if users are trained to tap without scrutiny.
Failure mechanism: A factor that demands repeated precision input or produces noisy prompts can drive unsafe user behaviour, such as weak workarounds, blind approvals, or support-driven bypasses. That weakens the effective assurance of the MFA program even if the factor is sound in theory.
Impact: Poor accessibility can reduce adoption, increase lockouts and exceptions, and create opening for phishing, social engineering, or fatigue-based abuse. The most secure factor on paper is not the one that users cannot complete reliably.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-63 and NIST SP 800-53 Rev 5 set the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-63 | Digital Identity Guidelines | Authenticator choice and usability are central to this accessibility comparison. |
| Recommendation — Select authenticators that balance assurance with user completion and accessibility. | ||
| NIST SP 800-53 Rev 5 | IA-2 — Identification and Authentication (Organizational Users) | MFA method choice affects how organizational users authenticate in practice. |
| IA-5 — Authenticator Management | Push and TOTP differ in authenticator handling, usability, and lifecycle burden. | |
| Recommendation — Implement user authentication methods that users can complete reliably. Manage authenticators to minimise friction while preserving authentication strength. | ||
| ISO/IEC 27001:2022 | A.5.17 — Authentication information | The question concerns how authentication information is used and handled by end users. |
| Recommendation — Provide authentication methods that are usable and appropriately controlled. | ||
Practitioner Guidance
What to verify: Test the actual sign-in journey with screen readers, keyboard-only navigation, mobile devices, and short timeout windows. If users cannot complete enrollment and sign-in without help, the method is not accessible enough for the population you are serving.
Decision rule: Use push where the user base needs the lowest-friction path and the platform can support meaningful approval context. Keep TOTP available where device diversity or offline compatibility matters, but treat it as the more demanding option and do not assume it is equally usable for all users.
Practitioner takeaway: The accessibility question is not which MFA method is stronger in isolation, but which one users can complete accurately and repeatedly without creating avoidable support burden or unsafe workarounds.
Related resources from NHI Mgmt Group
- What is the difference between time-based one-time passwords and magic links in passwordless authentication?
- What is the difference between biometric authentication and time-based one-time passwords in privileged access?
- What is the difference between time based and event based one time passwords for workforce authentication?
- What is the difference between push-based MFA and phishing-resistant authentication?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 24, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
