When purchasing an Azure subscription through CORE, it will need to be verified to prove ownership over the tenant. This is a security measure implemented by Microsoft in order to ensure that the provider has the required access and authority to perform such actions.
After purchasing the Azure subscription through the marketplace for your customer, you will see the following tile in their CORE account:
An instructional e-mail is set to their administrative contact on the account to notify them on how and what user to create in their Azure Active Directory, this user can be deleted after verification and does not need a license assigned.
The email received by the admin contact will appear as follows:
1. Sign in to https://portal.azure.com and create a new user with the verify-00a00 login in domain.onmicrosoft.com subdomain.
2. After user creating go back to Azure CSP and click "Verify" button.
Essentially they will need to create the user specified with their onmicrosoft.com domain - this can be created via either the Azure AD or Office 365 portals, and they do not need a license so there is no additional cost to creating this user. An example user would be:
Once the user is created you can click on Actions from within the Azure tab, and then Verify. If it doesn't verify immediately you may need to give it 5-10 minutes or so. If you wish for us to verify on your behalf, then we may do so by tailing the logs on the Azure endpoint, searching for the "VerifyUserName", but this would only be standard practice for migrations - new Azure setups should follow the e-mail as described.