Caller Authentication vs. Other Verification Methods

By Daniel Gniazdo on 30 March 2026

3 min read

<span id="hs_cos_wrapper_name" class="hs_cos_wrapper hs_cos_wrapper_meta_field hs_cos_wrapper_type_text" style="" data-hs-cos-general-type="meta_field" data-hs-cos-type="text" >Caller Authentication vs. Other Verification Methods</span>

Caller authentication via eIDs is a highly secure, fraud-resistant, and user-friendly way for companies to verify someone’s identity on the phone.

But it is far from the only one.

There are several traditional and emerging methods of identity verification, each with its strengths and weaknesses.

Let’s take a look at the most popular options and compare them to eID caller authentication.

What are the main ways to verify a caller’s identity?

While a company could come up with its own custom process for caller verification, the standard options are:

Security questions: The call center agent asks the caller to give the right answer to a stored personal “secret” (for instance, the name of their first pet).
PINs or passcodes: The caller enters a predefined PIN via the keypad on their phone, either in response to an agent request or an IVR prompt.
National ID numbers: In this case, the caller simply types in their national ID number while waiting for an agent.
One-time passwords (OTPs): The caller receives a system-generated one-off code via email or SMS and enters it to complete the verification.
Voice biometrics: The system matches a caller’s voice pattern to a stored voiceprint to verify their identity.

All of these methods rely on matching a caller’s input to an existing customer record.

eID-based caller authentication uses a fundamentally different approach.

How eID caller authentication works

eID-based caller authentication relies on national eID apps that most citizens already use.

Here’s how the process looks:

The agent triggers the authentication request.
The caller receives the request in their eID app and verifies on their device.
The agent sees the verified status, and the call continues.

It’s familiar, straightforward, and robust.

For a more comprehensive look, read: “How Exactly Does Caller Authentication Work?”

Caller authentication vs. other methods: Side-by-side

Here’s a top-level comparison of eID caller authentication against the rest:

eID caller authentication wins on every critical dimension, like security, fraud resistance, and verification speed. It might not be quite as effortless for the customer as voice biometrics, but for anyone with access to a national eID, it’s a familiar and trusted way to verify their identity.

Finally, eID-based caller authentication is the only method that lets companies verify callers who aren’t already customers, because it doesn’t rely on existing customer records. Instead, it uses a caller’s own eID app and credentials.

For a detailed comparison, consult the individual articles:

Why eID caller authentication is a smart choice

Every verification method comes with unique risks and challenges.

Knowledge-based authentication options like security questions and PINs are highly vulnerable to fraud and considered outdated. National ID numbers are quick to type in but offer no inherent proof of identity. One-time passwords are more robust, but they introduce additional friction while being susceptible to fraud via SIM swapping and compromised inboxes. Voice biometrics used to be a highly secure and friction-free alternative, but the rise of voice cloning and AI deepfakes is rendering it far less reliable.

That’s why eID caller authentication is growing in popularity and relevance. It addresses the weaknesses of the other methods without complicating the process for the end user. Anyone already using eID for logins and verification will know exactly how it works.

All of this makes eID caller authentication a highly secure, trustworthy, and future-proof choice for any company that needs to verify callers.

To learn more about its advantages, read “6 Business Benefits of Caller Authentication.”