# Missing Reservations for Steady Premium v3 and Isolated v2 App Service Plans

Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/missing-reservations-for-steady-premium-v3-and-isolated-v2-app-service-plans

Production App Service plans on Premium v3 (or later) and Isolated v2 often run a fixed minimum instance count all year: a web front end that never...

By: PointFive

Updated: 2026-09-28

[Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) 

The short version

Production App Service plans on Premium v3 (or later) and Isolated v2 often run a fixed minimum instance count all year: a web front end that never scales below two or three instances, or an App Service Environment sized for a steady line-of-business portfolio.

PointFive Research

Cloud cost research at PointFive

Azure service

[Azure App Service Plans](https://www.pointfive.co/efficiency-hub/cloud-services/azure-app-service-plans)

Category

[Compute](https://www.pointfive.co/efficiency-hub/service-category/compute)

Reference

CER-0404

Type

Suboptimal Pricing Model

## Explanation

Why the waste happens and who it affects.

Those instances are billed at the hourly pay-as-you-go rate even though the baseline is predictable.

App Service has its own reservation type, bought per region and instance size, separate from virtual machine reservations. Teams that manage commitments only for VMs, or that sized plans once and never revisited coverage, leave these plans uncovered. Microsoft states that Premium v3 reservations can cut the monthly cost by as much as 55% per instance, and Azure Advisor raises a dedicated reservation recommendation for App Service. Plans still on Premium v2 are not eligible and must move to Premium v3 or later first.

## Billing model

The pricing dimensions that drive this cost.

Plan instance

Each scaled-out instance is charged an hourly rate based on the plan's pricing tier, prorated to the second

App Service reservation

1- or 3-year commitment for Premium plan (v3 and later) or Isolated plan (v2 and later) instances of a given size and region

Use-it-or-lose-it

The discount applies hourly to matching running instances; unused reserved hours are lost and you still pay for them

Savings plan for compute

Hourly spend commitment that also covers Azure App Service, with more flexibility and usually less discount than a reservation

## How to detect

4 checks to find it in your estate.

- List App Service plans on Premium v3, Premium v4 and Isolated v2 SKUs and chart their instance count over the last 30 to 90 days; the lowest sustained count per region and size is the reservable baseline

- In Cost Management, filter to the App Service service and check the pricing model or benefit columns to see how much eligible usage is billed at pay-as-you-go rather than covered by a reservation or savings plan

- Review Azure Advisor for 'Consider App Service reserved instance to save over the on-demand costs' and the reservation purchase recommendations shown in the portal or benefit recommendation APIs

- Confirm that plans considered for reservation are not about to be resized, moved to another region or retired, since the reservation is tied to instance size and region

## How to fix

5 ways to remove the waste.

- Purchase App Service reservations for the steady minimum instance count per region and instance size, choosing a 1- or 3-year term and a shared or management group scope so the discount can follow instances across subscriptions

- Choose Linux-specific reservations only for Linux-only estates; the Windows (platform agnostic) type can apply to Windows or Linux instances

- Leave autoscaled burst capacity above the baseline on pay-as-you-go, or cover it with a savings plan for compute if usage is spread across regions and services

- Migrate eligible workloads from Premium v2 to Premium v3 or later before buying, since Premium v2 is not reservation-eligible

- Track reservation utilization after purchase and use exchanges when plan sizes change, rather than leaving reserved hours unused

## Documentation

Vendor references for pricing and configuration.

- [Save for Azure App Service with reserved capacity  learn.microsoft.com](https://learn.microsoft.com/en-us/azure/cost-management-billing/reservations/prepay-app-service)

- [Reservation discounts for Azure App Service  learn.microsoft.com](https://learn.microsoft.com/en-us/azure/cost-management-billing/reservations/reservation-discount-app-service)

- [Plan and Manage Costs for App Service  learn.microsoft.com](https://learn.microsoft.com/en-us/azure/app-service/overview-manage-costs)

- [Cost recommendations - Azure Advisor  learn.microsoft.com](https://learn.microsoft.com/en-us/azure/advisor/advisor-reference-cost-recommendations)

- [What are savings plans?  learn.microsoft.com](https://learn.microsoft.com/en-us/azure/cost-management-billing/savings-plan/savings-plan-overview)

- [Azure App Service on Windows pricing  azure.microsoft.com](https://azure.microsoft.com/en-us/pricing/details/app-service/windows/)

## Related inefficiencies

[Browse the library](https://www.pointfive.co/efficiency-hub)

- Azure App Service Plans  CER-0291

### [Overprovisioned Azure App Service Plan](https://www.pointfive.co/efficiency-hub/inefficiencies/overprovisioned-azure-app-service-plan)

An App Service Plan is sized larger than required for the applications it hosts. Plans are often provisioned conservatively to handle anticipated peak demand and are not revisited after workloads stabilize. Because pricing is tied to the...

Compute

- Azure App Service Plans  CER-0283

### [Mixing Production and Non-Production Applications in the Same App Service Plan](https://www.pointfive.co/efficiency-hub/inefficiencies/mixing-production-and-non-production-applications-in-the-same-app-service-plan)

Production and non-production applications are hosted within the same App Service Plan. Production workloads often require higher availability, performance, or scaling characteristics, driving the plan toward larger or higher-cost SKUs....

Compute

- Azure Virtual Machines  CER-0240

### [Azure Hybrid Benefit Not Enabled on Virtual Machines](https://www.pointfive.co/efficiency-hub/inefficiencies/azure-hybrid-benefit-not-enabled-on-virtual-machines-a8f4b)

Many organizations purchase Software Assurance or subscription-based Windows and SQL Server licenses that entitle them to use Azure Hybrid Benefit. However, if the setting is not applied on eligible resources, Azure continues charging...

Compute

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Source: the public page above. Product screenshots and illustrative interfaces are examples, not live customer data.

