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Caller Authentication does not work using twilio provider

User687957
Mega Guru

‎03-25-2026 06:35 AM

Dear all,

I have setup an Assistant provider as twilio for testing voice agent.From the configuration below I have setup the KBA for caller identification through phone number and set the caller authentication as Auth App
When calling the voice agent number, I manage to get identified by phone number but the second step for Auth App authentication fails all time by typing correct number
I have also try as MPF to set the SoftPin first but same thing
I have the feeling that MFA did not work at all in such context

Any one have experience this issue and any idea how to solve ?

regards

 

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2 REPLIES 2

pr8172510
Giga Guru

‎03-26-2026 04:10 AM

Hi,

 

What’s happening

Caller identification via phone number works fine, but Auth App / MFA (like OTP or push) does not always work reliably in Voice/IVR scenarios.

Reason:

  • MFA methods like Auth App are designed for interactive (UI) channels
  • In voice flows, there’s no native way to handle:
    • Push approvals
    • App-based verification
  • So the validation step often fails even if the input is correct

Why Soft PIN / MPF also fails sometimes

Even with Soft PIN:

  • Voice input (DTMF) handling can be inconsistent
  • Formatting or input timing can cause validation failure
  • Some MFA policies are not fully supported in Voice flows

What is supported / recommended

1. Use Voice-friendly authentication methods

For Voice Agent, stick to:

  • PIN-based authentication
  • Knowledge-based questions (KBA)
  • Phone number identification (ANI)

These are the most reliable.

2. Avoid Auth App for voice

Auth App (OTP / push) is:

  • Not designed for IVR flows
  • Not consistently supported via Twilio integration

3. Validate MFA configuration

Double-check:

  • MFA policy applied to users
  • Method allowed for API / non-interactive channels
  • Any restrictions on authentication context

4. Test outside Twilio

Try:

  • Same authentication via Web / Portal

If it works there but not in voice → confirms it’s a channel limitation

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User687957
Mega Guru
In response to pr8172510

‎03-26-2026 08:08 AM

hello @pr8172510 ,

 

Thanks for your reply, you mention that SoftPin and MFA does not work correctly with voice agent but from assistant designer and Authentication method you must select 2 manadantory things :
1- Caller identification ( enter phone number through key pad when configuring KBA)
2 - MFA by chosing either SoftPin or Auth App

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So I have no choice to enter this MFA configuration as it is mandatory.
The configuration above is what I actually have.

Now my main point is how to make it work ?


Q1: I do not understand how to verify points below, can you guide or clarify ?

Double-check:

  • MFA policy applied to users
  • Method allowed for API / non-interactive channels
  • Any restrictions on authentication context

Q2 : Same authentication via Web / Portal
MFA works correctly on web portal and active

There should be something wired because I cannot imagine ServiceNow supporting Twilio integration and fails in MFA authentication process.
The difference with MFA in web portal or any other login is base it is based on a user session.
Talking about voice , if MFA is supported as SoftPin for exemple, I guess they should build behind the user session based on the Caller Identification

Q3 : What is the way to check in kind of log table, the data which is post when I enter the SoftPin from my mobile keypad ?


Stuck for now and finding someone here who already succeed seems to be hard

 

Hoping you can help

 

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