Why your Azure bill keeps rising (and how to see where the money goes)

1. VMs larger than they need to be

Virtual machines are often sized for the busiest day, or by guesswork during a migration, and then never looked at again. If the processor runs below 20 to 25% most of the month, you pay for capacity you don't use. A smaller size in the same family often halves the cost.

2. Test and development running 24/7

A development VM used only during office hours often runs 168 hours a week. With automatic start and stop on weekdays, you pay for about a third of that.

3. Stopped, but not deallocated

Shutting a VM down from inside Windows or Linux stops the operating system, not the compute billing. Only when the Azure portal shows Stopped (deallocated) do you pay just for the disks.

4. Resources left behind after a migration

When a VM is deleted, its disks, snapshots and public IP addresses stay, and are billed every month. They go unnoticed because they are no longer attached to anything. This article explains how to find and safely remove them.

5. Services with nothing to do

An empty App Service plan, a load balancer without backends or a VPN gateway without connections costs as much as when they are fully used. They are often left behind after a project ended.

6. Growing logs

Log Analytics charges per ingested gigabyte, and for retention beyond the included period. A diagnostic setting that logs everything, or a year of retention where a month would do, grows unnoticed.

7. Licences you pay for twice

If you own Windows Server or SQL Server licences with Software Assurance, Azure Hybrid Benefit lets you use them in Azure. Without that setting, you pay for the licence again through Azure.

8. Reservations that no longer fit

A reservation for a VM size you have since changed no longer gives a discount, and an expired reservation quietly falls back to pay-as-you-go. See also which discount fits you.

See for yourself in Azure Cost Management

• In the Azure portal, open Cost Management → Cost analysis and view costs by resource and by service.
• Compare the last month with the months before: where is the increase?
• Group by resource group or tag to see which project or department is responsible.
• Set a budget with an email alert, so an increase doesn't surprise you on the invoice.