Clerk MFA

Clerk’s Two Factor Authentication (or Multi-Factor) Authentication (MFA) app allows you to receive verification codes from any online service. Clerk supports both virtual and non-VoIP phone numbers. Use Clerk on any website and speed up logging in with your partners and employees by receiving one-time passwords and verification codes.

Features:

Online SMS Verification
Shared Multi-factor Authentication
Use Numbers on Any Website
Create Unlimited Numbers
Receive Verification Codes in Seconds in:

Slack
Microsoft Teams
Email
Webhook
Forward to another Phone Number
API

Virtual Phone Numbers

A VoIP number, also known as Voice over IP number, is a virtual phone number that works with most online services to receive one-time passwords (OTP), but not all. A number of services can work with a virtual phone number via voice transcription.

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Note: By default when you provision a Clerk phone number in Slack you get assigned a virtual phone number.

Non VoIP (Real) Phone Numbers

Non-VoIP or Real phone numbers are usually required by highly sensitive websites such as banks, Facebook, Linkedin... This type of phone number will work with ALL online services.

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All Clerk Non VoIP numbers are USA based real phone numbers that will work with ALL online services.

To enable a non-voip number on your account please reach out to support@clerk.chat

Services

Refer to the following table for a breakdown of some of the popular supported services.

Service	Non VoIP (real)	VoIP (virtual)
ALL	✅
Alibaba	✅
Amazon	✅	✅
Apple	✅
Bill.com	✅
Brex	✅
Convoy	✅	✅
Chase	✅
Clubhose	✅
Craigslist	✅
Discord	✅
Facebook	✅
GoDaddy	✅
Google	✅
Gusto	✅
Hubspot	✅	✅
Instagram	✅
Intuit	✅
John Hancock	✅
LinkedIn	✅
Mailchimp	✅	✅
Microsoft	✅
Paypal	✅
SendGrid	✅	✅
Shopify	✅	✅
Snapchat	✅
Stripe	✅	✅
Telegram	✅
TikTok	✅
Tinder	✅
Twilio	✅
Twitter	✅
Uber	✅
Whatsapp	✅

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Limitations of Non VoIP Numbers: These types of phone numbers are designed for verification codes.

No Voicemail
No Call Forwarding
No SMS Campaigns

Turn on 2-Step Verification

Once your number has been assigned by Clerk copy and paste the number into your relevant service provider. You will get a confirmation SMS right inside of your workspace.

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Make sure to include a secondary backup phone number inside of your relevant accounts for emergency situations (i.e. service disruptions, network congestion...).

References