Allocate shared Azure platform costs transparently
On this page
Use management groups and subscriptions to organize accountable reporting boundaries, then use cost allocation rules to move supported shared-service costs among subscriptions, resource groups, and tags. Keep the allocated view separate from the invoice view because allocation does not change billing responsibility or the Azure invoice.
Why this is worth a look
Management groups organize subscriptions for governance and reporting, and can group subscriptions by business unit or another cost structure. Cost allocation rules redistribute shared-service costs among subscriptions, resource groups, and tags. Choose custom whole-number percentages totaling 100%, or a proportional basis using current-month total, compute, storage, or network cost. Allocated costs appear in Cost Analysis, downloaded Usage Details, and Exports, while the invoice and billing responsibilities remain unchanged.
Run this check
CHECKLISTComplete one read-only control record for each rule before creation, then retain it with the monthly chargeback package. Record currency amounts and the billing month used for verification.
RULE NAME:
OWNER AND REVIEW DATE:
AGREEMENT TYPE: MCA-E | MCA-online | EA
REPORTING BOUNDARY:
SOURCE TYPE: subscription | resource group | tag
SOURCE VALUES:
TARGET TYPE: subscription | resource group | tag
TARGET VALUES:
ALLOCATION BASIS: total cost | compute cost | storage cost | network cost | custom
CUSTOM WHOLE-NUMBER PERCENTAGES (TOTAL 100%):
BUSINESS DRIVER FOR EACH TARGET:
BILLING MONTH USED FOR PROPORTIONAL BASIS:
SOURCE COST BEFORE ALLOCATION (billing currency):
EXPECTED NEGATIVE SOURCE ENTRY:
EXPECTED POSITIVE TARGET ENTRIES:
COST ANALYSIS VERIFICATION DATE:
DOWNLOADED USAGE DETAILS VERIFIED: CostAllocationRuleName
EXPORT CSV VERIFIED: costAllocationRuleName
INVOICE RECONCILIATION COPY EXCLUDES ALLOCATED ROWS:
APPROVER AND EXCEPTION NOTES:How to confirm it
- 01
Set the reporting boundary
Use management groups to organize subscriptions by business unit, department, environment, or another reporting structure. Use subscriptions, resource groups, or tags as the documented cost-allocation dimensions, and record the boundary in the control record.
- 02
Choose source and targets
Identify the shared subscription, resource group, or tag as the source, then select subscriptions, resource groups, or tags as targets. Exclude purchases because cost allocation does not support purchases, including reservations and savings plans.
- 03
Select the allocation basis
Choose total cost, compute cost, storage cost, network cost, or custom. The proportional options use selected target costs for the current billing month. For custom, enter whole-number percentages whose total is 100%, and record the business driver for each target.
- 04
Review processing order
Review existing rules before creating another. Rules are processed in creation order, and a rule can take up to 24 hours to take effect. Record any ordering dependency and the date when the rule becomes active.
- 05
Verify reporting and reconcile
In a targeted resource group's Cost Analysis, group by Cost allocation. For tags, use Cost Analysis and filter by the tag key and values with allocated costs. In downloaded Usage Details and Export CSV files, verify the rule name and the negative source and positive target entries, then keep allocated rows out of the invoice-reconciliation copy.
Before making changes
Cost allocation currently supports MCA-E, MCA-online, and EA customers. Management groups are not currently supported in cost management features for MCA subscriptions. Proportional allocation uses costs for the current billing month, so record that billing month and the currency used for each verification. Cost allocation does not affect the invoice or billing responsibilities.