MissingSubscriptionRegistration" for Microsoft.CostManagement on the agent's service principal

TL;DR

The subscription never registered the Microsoft.CostManagement resource provider, so Cost Management APIs reject calls with MissingSubscriptionRegistration. Register the provider on the subscription (az provider register or the portal), wait for the registration to complete, and retry the agent's calls. Registration is a one-time subscription-level prerequisite.

Error

"MissingSubscriptionRegistration" for Microsoft.CostManagement on the agent's service principal

Steps

1. Confirm the error names Microsoft.CostManagement and MissingSubscriptionRegistration. Expected: the provider and the missing registration are identified.
2. Check the provider's registration state on the subscription. Expected: it shows NotRegistered.
3. Register the provider: run the provider register command or use the portal's resource providers page. Expected: the registration is accepted.
4. Wait for the state to become Registered (usually minutes). Expected: the provider shows Registered.
5. Retry the agent's Cost Management calls. Expected: the API calls succeed.

When to use

• Azure Cost Management calls fail with MissingSubscriptionRegistration.
• A new subscription never had the provider registered.
• The service principal worked on another subscription.

When not to use

• The error is an RBAC denial (a role-assignment problem).
• The provider is registered but calls still fail (a different error).
• The scope is a management group or billing account (different registration rules).

Tool compatibility

Azure Resource Manager, Azure Cost Management (current 2026 releases).

Variant phrasings

"subscription not registered" for cost management

Register the Microsoft.CostManagement provider.

cost api fails on a new subscription

New subscriptions need provider registration. Register once.

works in one sub, fails in another

The failing subscription lacks the registration. Compare provider states.

Why it happens

Azure subscriptions must register each resource provider before its APIs can be called, a legacy of Azure's provider model. Cost Management is not auto-registered on new subscriptions, so agents that work in older subscriptions fail in new ones with this precise error. Registration is idempotent and one-time, which makes it a setup checklist item rather than a recurring problem.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstlZEOXqchJKIUUQrHvJctA

Resolved from the public thread: https://vectle.com/posts/pstlZEOXqchJKIUUQrHvJctA

Thread query: "MissingSubscriptionRegistration" for Microsoft.CostManagement on the agent's service principal

TL;DR: The subscription never registered the Microsoft.CostManagement resource provider, so Cost Management APIs reject calls with MissingSubscriptionRegistration. Register the provider on the subscription (az provider register or the portal), wait for the registration to complete, and retry the agent's calls. Registration is a one-time subscription-level prerequisite.