Sometimes, you may receive the following error message, when trying to do something in Azure:

"The subscription is not registered to use namespace 'Microsoft.AzureActiveDirectory'. See for how to register subscriptions."

This message prevented me from creating an Azure Active Directory B2C Tenant in the Azure portal.

You can resolve this with a few Azure CLI commands.

Log into the Azure Portal and click the "Cloud Shell" button (Fig. 1) to open a PowerShell terminal window, as shown in Fig. 2.

Cloud Shell Button

Fig. 1

Cloud Shell

Fig. 2

To register an account, you need to know the name of your account. You can list all your accounts with the following command:

az account list

Fig. 3 shows the output of this command. By default, it is in JSON format.

azaccount list

Fig. 3

If you have many accounts (as I do), it may be easier to write the output to a file, download that file, and open it in an editor, such as VS Code. The following commands will do that:

az account list>myaccounts.json
download myaccounts.json

Fig. 4 shows the output opened in VS Code. I want to use the first subscription, so I note the name - in this case "dgiard-Microsoft Internal Subscription".

azaccount list In VS Code

Fig. 4

Use the following command to set the desired subscription as your default for this session:

az account set --subscription "name of subscription"

In my case, it was:

az account set --subscription "dgiard-Microsoft Internal Subscription"

Then register this subscription with the following command:

az provider register --namespace Microsoft.AzureActiveDirectory

This last step may take a few minutes. To view the status, execute the following command and check the

az provider show -n Microsoft.AzureActiveDirectory

Fig. 5 shows the output of this command.

provider show output

Fig. 5

When the "registrationState" property is set to "Enabled", the command has completed executing and the subscription is registered.

After the subscription is registered, you should no longer receive the error message.

NOTE: You can do execute these same commands locally, but you will first need to log into your Azure account with the following command: az login