Azure Managed Disk Billing Clarification - Premium SSD (P1) Disk Not Appearing in Cost Analysis and Billing Export

Question

Issue Summary

I need clarification regarding Azure Managed Disk billing behavior and how managed disk costs are represented in Azure Cost Management and Billing exports.

Scenario

I created an Azure Managed Disk with the following configuration:

• Disk Name: ajay-disk

Disk Type: Premium SSD

Disk Tier: P1

The disk was created successfully.

The disk has never been attached to any Virtual Machine.

The disk has remained in the Unattached (Available) state for approximately 3 days.

Expected Behavior

Based on Azure documentation, I expected the managed disk to incur storage charges even when it is unattached, since managed disks are generally billed based on provisioned capacity rather than actual usage.

However, after waiting for approximately three days:

No cost appears in Cost Analysis.

No billing record for this disk appears in the exported billing data.

The disk resource is also not visible in the billing export under any apparent meter or category.

Questions

I would appreciate clarification on the following:

1. Is an unattached Premium SSD P1 managed disk expected to generate charges immediately after creation?
2. If yes:
   • How long does it typically take before the charges appear in Cost Analysis and Billing Export?
   • Is there any minimum billing period before charges are reported?
3. How is Consumed Quantity calculated for managed disks?
4. What is the expected Consumed Unit for managed disks (Hours, Month, GiB-Month, Disk-Month, etc.)?
5. Is billing calculated based on:
   • Provisioned disk size,
   • Disk tier,
   • IOPS, Throughput,
   • Or another metric?
6. Does billing behavior differ between the following managed disk types?
   • Standard HDD
   • Standard SSD
   • Premium SSD
   • Premium SSD v2
   • Ultra Disk
7. For each managed disk type, could you explain:
   • When billing starts
   • What billing meters are used
   • How consumed quantity is calculated
   • What units appear in billing exports
   • Which cost categories should be expected

Additional Information

My objective is to correctly interpret Azure billing exports and accurately map managed disk costs in our cost optimization platform. Understanding how each managed disk type is billed and how those charges are represented in billing data is important for our implementation.

Could you please explain the expected billing behavior and help determine why this particular Premium SSD P1 disk has not generated any billing records after several days?

Thank you.

Answer 1

Thank you for the response, based on Microsoft’s Azure Managed Disks billing documentation, Premium SSD disks are billed based on the selected Premium SSD performance tier, and charges are prorated from the monthly price when the disk is incurring billable storage usage. However, one important nuance is that for a newly created empty managed disk, Azure initially stores only disk metadata. The underlying storage is allocated when the disk is first used, such as when it is attached to a VM or when a VHD is uploaded. If the empty disk has not been used and no underlying storage has been allocated, it may not incur disk storage charges.

Premium SSD and Premium SSD v2 use different billing models. Premium SSD v2 is billed using separate components for provisioned capacity, provisioned IOPS, and provisioned throughput. Premium SSD P-tier disks, such as P1, are billed using a fixed disk-tier meter based on the selected performance tier, with additional meters only for specific features such as on-demand bursting where applicable.

Therefore, if the P1 disk was created but never attached to a VM or otherwise used, it may be expected that no billing record is visible. If the disk was attached or used, then it should generate prorated usage records, although very small P1 charges may be difficult to identify in Cost Analysis due to low daily cost, billing data latency, export schedule, credits, or rounding behavior.

To validate, please review the raw Cost Details / Usage and Charges file or the Cost Details API rather than relying only on Cost Analysis. Filter by the disk’s ResourceId or by the relevant meter category, such as Premium SSD Managed Disks, and group by Meter or Resource. Please ensure the date range includes the disk creation and usage period, and review Actual Cost; Amortized Cost can also be checked if credits, reservations, or commitment-based benefits may affect cost visibility.

Referance: Understand Azure Disk Storage billing Managed disk types - Billing Managed Disks pricing

Answer 2

hi Ajay Kumar & thx for sharing urs issue here at Q&A portal,

yes, an unattached managed disk is still billable. It doesn’t need to be attached to a VM.

For Premium SSD P1, billing is mainly based on the provisioned disk tier/size, not actual used data. So an unattached P1 disk should start generating storage charges after creation.

If it doesn’t show after 3 days, check Cost Management scope/date filters first. Costs can lag, but 3 days is long enough that u should usually see something unless the cost is very small, filtered out, covered by credits, or grouped under a meter name that doesn’t obviously show the disk name. In exports, managed disk charges may show under storage/disk meters, and the resource ID should normally be the disk resource. But some views aggregate by meter/resource group/subscription, so it can be easy to miss.

Premium SSD charged by provisioned disk tier/size, like P1/P2/etc.

Standard HDD/SSD generally charged by provisioned capacity + transactions depending on type.

Premium SSD v2 and Ultra Disk: billed differently, usually provisioned capacity + provisioned IOPS/throughput.

For ur case, I’d export cost data for the full subscription, group by MeterCategory, MeterSubCategory, MeterName, ResourceId, and filter around the resource group. If still no line for ajay-disk, open a billing support case w/ disk resource ID, region, SKU/tier, creation time, and export sample. Billing support can confirm if the meter was generated or suppressed/credited.

rgds,

Alex

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