Hello @Ben Newall Thank you for reaching out to us on Microsoft Q&A platform. Happy to answer any questions you may have!
I have reviewed your post and I understand that you have an Azure account with the "Microsoft Azure Sponsorship" offer. It turns out that the Microsoft Azure Sponsorship offer does not yet support Cost Management data and you will need to change offers to one of the listed offers in order to obtain access to Cost Management data. Please refer to the following document here for a list of the current supported and unsupported offer types that support Cost Management.
You can view the Costs for azure sponsorships at - https://www.microsoftazuresponsorships.com/Usage.
Hope this helps. Feel free to get back to us if you have any questions!
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