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Tag your Amazon EC2 resources

To help you manage your instances, images, and other Amazon EC2 resources, you can assign your own metadata to each resource in the form of tags. Tags enable you to categorize your Amazon resources in different ways, for example, by purpose, owner, or environment. This is useful when you have many resources of the same type—you can quickly identify a specific resource based on the tags that you've assigned to it. This topic describes tags and shows you how to create them.

Tag basics

A tag is a label that you assign to an Amazon resource. Each tag consists of a key and an optional value, both of which you define.

Tags enable you to categorize your Amazon resources in different ways, for example, by purpose, owner, or environment. For example, you could define a set of tags for your account's Amazon EC2 instances that helps you track each instance's owner and stack level.

The following diagram illustrates how tagging works. In this example, you've assigned two tags to each of your instances—one tag with the key Owner and another with the key Stack. Each tag also has an associated value.

We recommend that you devise a set of tag keys that meets your needs for each resource type. Using a consistent set of tag keys makes it easier for you to manage your resources. You can search and filter the resources based on the tags you add. For more information about how to implement an effective resource tagging strategy, see the Tagging Best Practices Amazon Whitepaper.

Tags don't have any semantic meaning to Amazon EC2 and are interpreted strictly as a string of characters. Also, tags are not automatically assigned to your resources. You can edit tag keys and values, and you can remove tags from a resource at any time. You can set the value of a tag to an empty string, but you can't set the value of a tag to null. If you add a tag that has the same key as an existing tag on that resource, the new value overwrites the old value. If you delete a resource, any tags for the resource are also deleted.

Tag your resources

When you use the Amazon EC2 console, you can apply tags to resources by using the Tags tab on the relevant resource screen, or you can use the Tags Editor in the Amazon Resource Groups console. Some resource screens enable you to specify tags for a resource when you create the resource; for example, a tag with a key of Name and a value that you specify. In most cases, the console applies the tags immediately after the resource is created (rather than during resource creation). The console might organize resources according to the Name tag, but this tag doesn't have any semantic meaning to the Amazon EC2 service.

If you're using the Amazon EC2 API, the Amazon CLI, or an Amazon SDK, you can use the CreateTags EC2 API action to apply tags to existing resources. Additionally, some resource-creating actions enable you to specify tags for a resource when the resource is created. If tags cannot be applied during resource creation, we roll back the resource creation process. This ensures that resources are either created with tags or not created at all, and that no resources are left untagged at any time. By tagging resources at the time of creation, you can eliminate the need to run custom tagging scripts after resource creation. For more information about enabling users to tag resources on creation, see Grant permission to tag Amazon EC2 resources during creation.

You can apply tag-based resource-level permissions in your IAM policies to the Amazon EC2 API actions that support tagging on creation to implement granular control over the users and groups that can tag resources on creation. Your resources are properly secured from creation—tags are applied immediately to your resources, therefore any tag-based resource-level permissions controlling the use of resources are immediately effective. Your resources can be tracked and reported on more accurately. You can enforce the use of tagging on new resources, and control which tag keys and values are set on your resources.

You can also apply resource-level permissions to the CreateTags and DeleteTags Amazon EC2 API actions in your IAM policies to control which tag keys and values are set on your existing resources. For more information, see Example: Tag resources.

For more information about tagging your resources for billing, see Using cost allocation tags in the Amazon Billing User Guide.

Tag restrictions

The following basic restrictions apply to tags:

You can't terminate, stop, or delete a resource based solely on its tags; you must specify the resource identifier. For example, to delete snapshots that you tagged with a tag key called DeleteMe, you must use the DeleteSnapshots action with the resource identifiers of the snapshots, such as snap-1234567890abcdef0.

When you tag public or shared resources, the tags you assign are available only to your Amazon account; no other Amazon account will have access to those tags. For tag-based access control to shared resources, each Amazon account must assign its own set of tags to control access to the resource.

Tags and access management

If you're using Amazon Identity and Access Management (IAM), you can control which users in your Amazon account have permission to create, edit, or delete tags. For more information, see Grant permission to tag Amazon EC2 resources during creation.

You can also use resource tags to implement attribute-based control (ABAC). You can create IAM policies that allow operations based on the tags for the resource. For more information, see Control access using attribute-based access.

Tag your resources for billing

You can use tags to organize your Amazon bill to reflect your own cost structure. To do this, sign up to get your Amazon account bill with tag key values included. For more information about setting up a cost allocation report with tags, see Monthly cost allocation report in the Amazon Billing User Guide. To see the cost of your combined resources, you can organize your billing information based on resources that have the same tag key values. For example, you can tag several resources with a specific application name, and then organize your billing information to see the total cost of that application across several services. For more information, see Using cost allocation tags in the Amazon Billing User Guide.

Cost allocation tags can indicate which resources are contributing to costs, but deleting or deactivating resources doesn't always reduce costs. For example, snapshot data that is referenced by another snapshot is preserved, even if the snapshot that contains the original data is deleted. For more information, see Amazon Elastic Block Store volumes and snapshots in the Amazon Billing User Guide.