In this guide 7 sections
Agree a short set of tag keys, such as service, environment and owner, and apply them to every resource. Activate them as cost allocation tags, then enforce them on new resources. Tagging comes before any cost cutting. GullySystem’s cloud cost review starts by tagging every resource to an owner.
Why tagging comes first
A cloud invoice lists services, not purposes. It shows the spend on compute, not which product or customer used it.
Tags attach a purpose to each resource. Once they are in place, a rise in the bill can be traced to the service, environment and team behind it, rather than noticed months later at renewal.
Without tags, nobody switches anything off. Nobody knows what depends on a server called test-2.
Choose a small set of keys
Start with four or five keys. Beyond that, people stop filling them in.
Fix the allowed values as well. If one team writes prod and another writes production, the report splits into two lines.
- service: the product or application
- environment: production, staging, test or demo
- owner: a named person or team
- customer: for per-tenant or per-client setups
- expiry: a date for anything temporary
Tag what already exists
List every resource in the account. Ask each team to claim what is theirs. Expect gaps.
Some resources will have no claimant. Treat each as a question, not a deletion. Stop it for a period before removing it, so recovery is quick if something breaks.
Shared items, such as a network gateway, need a rule. Assign them to a shared service, or split their cost by an agreed key.
Make tags show up on the bill
On AWS, user-defined tags must be activated as cost allocation tags before billing reports show them. AWS documentation says keys can take up to a day to appear, and up to another day to activate.
Azure and Google Cloud have their own steps for tag and label reporting. Check each provider’s billing documentation.
Then group the bill by tag. Look at the untagged line first. It shows how much spend is still unexplained.
Keep new resources tagged
Tags decay unless new resources arrive labelled. Infrastructure templates, such as Terraform, can apply tags by default.
Policies can reject untagged resources outright. A monthly review of the untagged line catches what slipped through.
- Default tags in infrastructure templates
- A policy that blocks untagged resources
- An expiry tag on every temporary environment
- A monthly look at untagged spend
Tagging scheme sheet
A one-page sheet listing each tag key, its allowed values, an example and who sets it. A second tab lists every untagged resource with a column for its owner. Work down that tab until it is empty.
Open a blank worksheet to printQuestions owners ask
Does tagging reduce the bill?
Not on its own. Tagging makes the bill readable. Savings come from what follows, such as removing idle resources and right-sizing.
How many tags are too many?
If people skip them, there are too many. Four or five keys with fixed values usually cover service, environment, owner and any cost split.
Who should own tagging?
One person sets the scheme and reviews the untagged line each month. Each team tags its own resources, since it knows what they are for.
Sources
- AWS Billing: Activating user-defined cost allocation tags — verified 6 Oct 2026