During AWS re:Invent 2014, J.R. Storment from Cloudability did a session titled “Creating a Culture of Cost Management in Your Organization”. You can view this session on YouTube:
During this session, he mentioned a policy called “Tag or Terminate”. Basically, he says that if an instance has been up for 24-hours and it hasn’t been tagged according to your tagging policies, then the instance could be stopped. This can be an effective way to enforce your tagging policies for costing and reporting.
You can see this at 14:05 in the video.
Skeddly has an action called “Stop Multiple EC2 Instances” which can be used as an enforcement tool for such a policy. Using this action, you can stop any instances which are missing an important tag.
The extra good news: having this action scheduled to run daily won’t cost anything unless there is actually an EC2 instance which is missing the tag and is being stopped.