Tag restrictions - Amazon Certificate Manager
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Tag restrictions

The following basic restrictions apply to ACM certificate tags:

  • The maximum number of tags per ACM certificate is 50.

  • The maximum length of a tag key is 127 characters.

  • The maximum length of a tag value is 255 characters.

  • Tag keys and values are case sensitive.

  • The aws: prefix is reserved for Amazon use; you cannot add, edit, or delete tags whose key begins with aws:. Tags that begin with aws: do not count against your tags-per-resource quota.

  • If you plan to use your tagging schema across multiple services and resources, remember that other services may have other restrictions for allowed characters. Refer to the documentation for that service.

  • ACM certificate tags are not available for use in the Amazon Web Services Management Console's Resource Groups and Tag Editor.

For general information about Amazon tagging conventions, see Tagging Amazon Resources.