Last month summary

Overview

Last month summary is a tab on the Overview of a Cost Analyzer cost management group. It shows the last completed calendar month in amortized cost, compared with the month before it, so you can review a group's month-end spend in one place. The tab is read-only. It has no month picker and contains no AI-generated content.

The group Overview has two tabs: Essentials, which is selected by default, and Last month summary. The month and year, for example September 2026, appear at the right end of the tab row while Last month summary is selected.

Business value

Last month summary puts the month-end review of a group on one page. You can check total spend, the services and subscriptions behind it, and any anomalies, budget alerts, and reservation issues without opening Analysis, Monitoring, and Optimization separately.

Prerequisites

The tab needs a group with mapped subscriptions and imported cost data for the month under review and the month before it.

Required permissions

Any user who can open a group's Overview can see the Last month summary tab, the tiles, Daily cost, Cost drivers, and Notable movers. Three cards depend on feature permissions. See Roles and permissions in Cost Analyzer to assign them.

Dependencies

• Mapped subscription: the group must have at least one mapped subscription. Without one, the tab shows Map a subscription to this group to see last month's summary.
• Imported cost data: cost must be imported for last month and the month before it, for every mapped subscription.
• Anomaly detection: the Anomalies card shows alerts raised by Automatic anomaly detection.
• Group budget: the Budget alerts card shows incidents from Group budget monitoring.
• Reservations: the Reservation utilization card uses the reservations mapped to the group.

How it works

The tab covers the last completed calendar month in UTC. Every figure is amortized cost except the Actual cost tile. When the subscriptions in a group share one billing currency, the summary shows amounts in that currency as is. Cost is converted to USD only when a group mixes currencies. A profit margin set on the group is applied to the amounts shown.

Tiles. Four tiles sit in one row at the top of the tab.

The tile totals and the sum of the daily bars can differ slightly.

Cards. The cards below the tiles show the detail behind the totals.

The Anomalies, Budget alerts, and Reservation utilization cards appear only when the group has data for them. Anomalies and Budget alerts are read live each time, so their statuses are current.

Notable movers. Movers are normalized to 30 days: the month total divided by the days in the month, multiplied by 30. The card labels this Per 30 days · amortized, and adds the converted currency for mixed-currency groups. A group with a very large number of resources shows resource group movers instead of resource movers.

Preparing and refreshing data. When you open the Overview, Cost Analyzer starts preparing the summary in the background, so it is usually ready when you open the tab. The Top cost driver tile, Cost drivers, and Notable movers can take longer for groups with a lot of cost data. While they are prepared, the tile shows Still being prepared and the cards explain that their data will appear when ready. You can keep working. A toast with the message Cost drivers and notable movers for last month are ready. appears when the data arrives. If cost is still being collected, or a section fails to load, the tab updates the content when it is ready, without a loading placeholder. A section that is still loading appears when it is ready; refresh the page after a few minutes.

Caching. Cost Analyzer reuses a saved copy of the summary for up to 1 day. It rebuilds the summary immediately when the group's scope, filters, profit margin, cost allocation rules, or reservation mapping changes. Reset cached data under Tools in the group context menu also clears the saved copy, and the next time you open the tab, the summary is rebuilt.

Steps

Use the following steps to read and work with the summary. Navigate to Cost Analyzer, select the group in the tree view, and open the Overview tab to get started.

Open the summary

Opening the tab shows last month's spend for the group at a glance.

1. Select the group in the tree view.
2. Click Overview.
3. Click the Last month summary tab. The month and year appear at the right end of the tab row.

Switch the cost driver view

Switching the view lets you see which services, subscriptions, or resource groups drove last month's cost.

1. In the Cost drivers card, click Services, Subscriptions, or Resource groups.
2. Compare the cost, share of spend, and change against the previous month for each row.

Filter notable movers

Filtering the movers lets you focus on one kind of change, such as new charges.

1. In the Notable movers card, click a count pill, for example 3 increased, to show only that kind of change.
2. Click the pill again, or click All, to return to both columns.
3. Click +N more to expand a column, and click Show less to collapse it.

View all anomalies

Opening the full list takes you from the summary to the anomaly details.

1. In the Anomalies card, click View all N anomalies. The link appears when there are more than 5 anomalies.
2. Cost Analyzer opens Monitoring > Anomaly detection for the group.

Reset cached data

Resetting cached data forces the summary to rebuild with the latest cost data.

1. Click the Context menu ( ⋮ ) next to the group in the tree view.
2. Select Reset cached data under Tools.
3. Click Reset. To clear the child groups as well, select Include subgroups first.

Permission behavior

Without the matching Read permission, the Anomalies, Budget alerts, and Reservation utilization cards are hidden. They are not shown disabled, and no error appears. The View all N anomalies link is available only when the Anomalies card is visible.

Example scenario

On 4 October 2026, a FinOps lead opens the Production group, clicks Overview, and then clicks Last month summary. The tab row shows September 2026.

The Amortized cost tile shows €48,210.55, which is €3,105.20 (6.9%) more than August. The Actual cost tile shows €61,400.00, which is €13,189 above amortized cost because an upfront reservation purchase landed in September. The Top cost driver is virtual machines, at 41% of spend.

The group is large, so the Cost drivers card first says its data is still being prepared. About two minutes later, a toast confirms the data is ready. The lead has Read on Anomaly detection and Group budget, so the Anomalies card shows 7 detected anomalies and the Budget alerts card shows one open incident. The lead doesn't have Read on Reservations, so the Reservation utilization card isn't shown.

Limitations

• The tab shows only the last completed month in UTC, compared with the month before it. There is no month picker.
• You can't export, print, or email the summary.
• Cost drivers lists up to 8 rows per view. Anomalies, Budget alerts, and the Least used reservations list show up to 5 rows each.
• Resource groups that have the same name in different subscriptions appear as separate rows with the same name.
• The tiles can show partial figures while cost data is still being collected for a subscription.

Troubleshooting

1. A section shows a message such as Cost drivers couldn't be loaded. with a Try again button
   Cause: the section timed out or failed to load. Cost drivers and Notable movers also show this message when they are still being prepared after several minutes.
   Fix: click Try again. A section that fails to load is also retried automatically. If the section still doesn't load, refresh the page after a few minutes.

2. The tab shows Last month's cost data is still being collected. It will appear here once collection completes.
   Cause: the cost import hasn't yet covered both months for every mapped subscription.
   Fix: wait for the cost import to finish. The tab updates when the data is ready. If it doesn't, refresh the page after a few minutes.

3. The tab shows Map a subscription to this group to see last month's summary.
   Cause: the group has no mapped subscriptions.
   Fix: add a subscription to the group by using Edit scope. See Managing cost groups.

4. The Anomalies, Budget alerts, or Reservation utilization card is missing
   Cause: your role doesn't have Read on Anomaly detection, Group budget, or Reservations, or the group has no anomalies, budget alerts, or reservations for the month.
   Fix: ask an administrator to grant the matching Read permission. If you already have it, no data exists for that card in the month.

5. The figures look outdated after a change to the group
   Cause: Cost Analyzer reuses a saved copy for up to 1 day, and it normally rebuilds the copy when the group changes.
   Fix: click the Context menu ( ⋮ ) next to the group, select Reset cached data under Tools, and click Reset.

FAQs

1. Can I view a month other than last month?
   No. The tab always shows the last completed UTC month. Use Analysis to look at other periods.

2. Can I export or share the summary?
   No. The tab has no export, print, or email option.

3. Why do the Notable movers amounts differ from the monthly totals?
   Movers are normalized to 30 days so months of different lengths compare fairly. The card is labeled Per 30 days · amortized.

Related articles

• Cost management groups
• Managing cost groups
• Roles and permissions in Cost Analyzer
• Automatic anomaly detection
• Group budget monitoring