If you are evaluating Microsoft Fabric and do not currently own a Premium Capacity, chances are you’re using Microsoft Fabric Trial Capacities. All Power BI users within an organisation or specific security groups given the rights can opt into Fabric Trial Capacities. Therefore, you may already have several Trial Fabric Capacities in your tenant. Your Fabric Administrators can specifically control who can opt into the Fabric Trial capacities within the Fabric Admin Portal, on the Help and support settings section, and enabling the Users can try Microsoft Fabric paid features setting as shown in the following image:

The authorised users can then opt into Fabric Trial by following this process:

1. Click the Account Manager on the top right corner of the page
2. Click the Start trial button
3. Click the Start trial button again
4. Provide the required details
5. Click the Extend my free trial button

The following image shows the preceding steps:

As you see, opting into Fabric Trial is simple, unless it isn’t!

There are cases where authorised users cannot start their Fabric Trial because their tenant has already exceeded the limit of available trial capacities. In that case, the users get the following message:

Unable to sign up for the Microsoft Fabric trial
We cannot assign you a free Microsoft Fabric trial capacity because your Microsoft tenant has reached the maximum number of available free trial capacities.

If we do some digging, we find out that the limited number of available trial capacities is documented in the official Micrsoft Learn’s website. To sum up the documentation, the users who face this issue have a couple of options being:

• Purchase a Fabric capacity
• Ask another trial capacity user to give you access to a workspace assigned to their trial capacity
• Ask your Fabric administrator(s) to create a Microsoft support ticket to increase your tenant’s capacity limits

These solutions are all straightforward. But you may face some unexpected roadblocks. In some cases, many people within the organisation want to learn Microsoft Fabric. However, the organisation’s governance policies do not allow the creation of workspaces on the production tenant for self-learning purposes. Instead, the users must use their Personal Workspace for learning purposes.

This blog post focuses on looking at our options to overcome this challenge.

Assign a Personal Workspace to an Existing Fabric Trial Capacity

We have two options requiring the Fabric Admin role as follows:

• Reassign personal workspaces from the Fabric Admin Portal
• Use Power BI REST APIs to assign workspaces to a Fabric trial capacity

Reassign Personal Workspaces from the Fabric Admin Portal

Follow these steps to Reassign personal workspaces if you are a Fabric administrator:

1. Within the Admin Portal click the Workspaces tab
2. Select a personal workspace
3. Click the Reassign Workspace from the ribbon
4. Select the Trial option
5. Click the Save button

As we see, the personal workspace is now assigned to a trial capacity.

It looks like it did the trick, but there is a caveat. This method works fine if we have only one Fabric trial capacity in the tenant. As we saw earlier, we have yet to be given the option to select a specific Fabric capacity. Instead, we just selected the Trial license mode. In my tests on a tenant with multiple trial capacities, the above process always assigned the workspace to the newer capacity (the capacity that was created last). But what if you want to assign the personal workspaces to a specific capacity and not to every capacity? Power BI APIs to the rescue!

Use Power BI REST APIs to assign workspaces to a Fabric trial capacity

As mentioned before, we must be a Fabric Admin to implement this method successfully. The required API is the Admin – Capacities AssignWorkspacesToCapacity. This API’s method is POST, so we need to pass the list of workspace IDs and the capacity ID to the API’s Body. The Body for this API must follow this structure:

{
  "capacityMigrationAssignments": [
    {
      "targetCapacityObjectId": "CAPACITY_ID",
      "workspacesToAssign": [
        "WORKSPACE_ID1"
        , "WORKSPACE_ID2"
        , ...
      ]
    }
  ]
}

We have a couple of options to get the capacity ID and workspace IDs, such as using Microsoft Fabric’s User Interface (UI), Explore the Feature Usage and Adoption semantic model under the Admin Monitoring workspace of the Microsoft Purview hub, and running Admin REST APIs. The simplest way for the purpose of this blogpost is to use Microsoft Fabric’s web UI. To keep this blog short and simple, we use the web UI to capture the capacity and workspace IDs. I will write a separate blog to explain the Microsoft Purview hub setup and usage, so stay tuned!

Get Capacity ID in Microsoft Fabric

Login to your Microsoft Fabric account and navigate to the Admin Portal. Follow these steps to get the desired capacity ID:

1. Click the Capacity settings tab
2. Click the desired capacity type; in our case, we are after a Fabric Trial capacity, so we click the Trial tab
3. Click the Settings for the desired capacity under the Actions column
4. The Capacity ID appears at the bottom of the capacity Settings page

The following image shows these steps:

Get Workspace ID in Microsoft Fabric

On Microsoft Fabric, navigate to the Admin Portal, then follow these steps:

1. Select the Workspaces tab
2. Hover over the desired Personal Workspace and click the Actions ellipsis button
3. Select the Details option
4. The workspace ID shows up

The following image shows these steps:

Run Admin/Capacities/AssignWorkspaces REST API

Now that we have the capacity ID and workspace ID handy, we can go ahead and run the POST https://api.powerbi.com/v1.0/myorg/admin/capacities/AssignWorkspaces REST API.

I am a big fan of the Try It capability in the Power BI REST API pages that enables us to literally run the APIs without writing a single line of code, which is perfect for running one-off activities. Follow these steps to run the API directly from the API documentation webpage:

1. Visit Microsoft Learn documentation for the admin/capacities/assignworkspaces API
2. Click the Try It button

Tip

If this is the first time you use this feature, you need to agree with and give the required consent.

3. On the Confirm your account click the Continue with Account button

4. Copy/paste the Body part as shown here

Note

Remember to replace the CAPACITY_ID and WORKSPACE_ID with the IDs captured from the Microsoft Fabric UI.

5. Click the Run button

We will get Response Code: 200 if the API successfully runs, as shown in the following image:

If we check the Workspaces on the Admin Portal, we see that the personal workspace is now assigned to the desired capacity.

Conclusion

While Microsoft generously offers a free Fabric trial capacity to empower organisations to learn this technology, certain limitations may present roadblocks for users exploring Microsoft Fabric. This blog has tackled these challenges, focusing on effective solutions like assigning Personal Workspaces to existing Fabric Trial capabilities, ensuring a smoother learning experience for the users. Understanding and overcoming these limitations is key for administrators navigating governance policies in their organisations.

As always, I invite you to share your thoughts in the comments below. Follow me on X (Twitter) and LinkedIn to get notified of my new posts.