The end of the calendar year is the right time to review actual Azure spend, assess what changed during the year, and set a realistic budget for the year ahead. A well-structured budget is not just a financial control; it is a governance tool that keeps engineering and finance aligned throughout the year.
This post outlines a practical framework for reviewing the current year's spend and setting up Azure budgets for the next 12 months.
1. Reviewing the Current Year's Spend
Before setting next year's budget, it is important to understand this year's patterns, particularly which resource groups grew significantly, which were decommissioned, and whether any anomalies inflated the total.
- Navigate to Cost Management + Billing > Cost Analysis
- Set the Time range to This year (or the last 12 months if the current year started recently)
- Set Granularity to Monthly and Group by to Resource group
This view shows the month-by-month cost trend per resource group. Look for:
- Resource groups with consistent growth: these need a higher budget allocation next year
- Months with spikes: investigate whether these were one-time events (migrations, incidents) or recurring patterns
- Resource groups with zero activity in recent months: candidates for decommission
2. Estimating Next Year's Budget
A practical estimation approach is to take the last three months of spend (Q4 of the current year), calculate the average monthly cost, and apply a growth factor based on planned workload changes.
Following is a simple framework:
| Input | Example |
|---|---|
| Average monthly spend (last 3 months) | $4,200 |
| Planned new workloads | +15% |
| Expected optimisation savings | -10% |
| Estimated monthly budget | $4,410 |
| Annual budget | $52,920 |
Add a buffer of 5–10% to the annual budget to account for unplanned usage. Setting the budget too tightly leads to constant alert noise; setting it too loosely removes the governance benefit.
3. Creating Annual and Monthly Budgets
Azure Cost Management supports budgets at multiple time grains. For annual planning, I recommend creating both an annual budget at subscription or management group scope and monthly budgets at individual resource group scope.
To create a budget:
- Navigate to Cost Management + Billing > Cost Management > Budgets > + Add
- Set the Reset period. Select Annually for the top-level budget and Monthly for resource group budgets
- Set the Budget amount based on the estimate from Step 2
- Configure alert thresholds at 50%, 80%, and 100%
- Add email recipients for each threshold. Include both the engineering lead and a finance contact
4. Using the Forecast to Validate the Budget
Azure Cost Management includes a spend forecast based on historical usage patterns. This is a useful sanity check before finalising budget amounts.
Navigate to Cost Management > Cost Analysis and set the view to Accumulated costs. The forecast line (shown in a lighter colour beyond the current date) projects spending to end of period based on current trajectory.
If the forecast significantly exceeds the proposed budget, either adjust the budget upward or identify specific optimisation actions that will reduce spend before the new year begins.
5. Scheduling a Quarterly Budget Review
A budget set in January rarely reflects reality by June. Build in a quarterly review. At each review, compare actual spend against budget, assess whether planned workloads have materialised as expected, and adjust budgets or resource allocations accordingly.
Summary
Effective Azure budget planning starts with an honest review of the current year's data, followed by a realistic estimate that accounts for planned growth and known optimisations. Configuring budgets with graduated alert thresholds (not just a single 100% alert) ensures that teams have time to respond before limits are reached, avoiding surprises at year-end billing reconciliation.
