Virtual machines can be migrated from Pay‑As‑You‑Go (PAYG) to Cloud Solution Provider (CSP) subscriptions even if they are currently covered by Reserved Instances (RIs).
However, the Reserved Instance itself does not move with the VM.
- Azure Reserved Instances are billing constructs, not VM properties.
- Because of this, VM migration is fully supported, and RIs do not restrict or block the move.
Important distinction
- PAYG > CSP is not a subscription transfer.
- CSP requires a new Azure subscription, meaning billing constructs like RIs and Savings Plans cannot be carried over.
What happens to the existing RI
- The PAYG Reserved Instance remains active in the original subscription.
- If no eligible resources remain, the RI simply goes unused until expiration.
- Microsoft does not support converting PAYG RIs into CSP.
After migration
- Migrated VMs in CSP will be billed at pay‑as‑you‑go rates
- A new RI must be purchased under CSP to regain reservation benefits.
Best practice we recommend:
- Migrate workloads first (Azure Resource Mover).
- Validate functionality and billing in CSP.
- Purchase new RIs under CSP aligned to the desired scope.
Why doesn’t documentation mention this directly https://learn.microsoft.com/en-us/partner-center/customers/transfer-azure-subscriptions-under-azure-plan?wt.mc_id=knowledgesearch_inproduct_azure-cxp-community-insider#considerations
- The Partner Center article applies only to CSP‑to‑CSP transfers, where subscriptions and reservations move together.
- Since PAYG subscriptions are outside the CSP model, RI behavior in this scenario is not documented there.
If you have any further queries, let me know. If the information is helpful, please click on Upvote and Accept Answer on it.