When an organization has two Vanta instances, or a user is present in two different identity providers on two different domains, they will not be able to sign in using an identity provider. This means the all of the SSO sign in options will lot work (Google, Microsofty, Okta, OneLogin).  The user will need to use the sign in with email option:

Steps

1. When signing into Vanta, select the continue with  email option, where a text box will appear for you to enter your Vanta associated email:
   
   
   
   Once the email is entered, click continue wth email. 
   
   
   
2. You should receive an email from noreply@vanta.com shortly afterwards. If you do not see it in your inbox check your spam box. Click the 'Click here' link to be taken to the sign in page:
   
   
   
   
3. This page will allow the user to decide which Vanta instance they wish to sign into:
   
   
   
   

Additional Resources

•  Switching Identity Providers - What should I know?
• Error: "Unable to load user from identity provider"