Ensure that all purchased AWS EC2 Reserved Instances (RI) have corresponding instances running within the same account or within any linked AWS accounts available in an AWS Organization (if you are using one). A corresponding instance is an EC2 instance (i.e. virtual server) provisioned based on the existing RI reservation criteria such as Region, Instance Type, Tenancy and Platform (OS).
When an AWS EC2 Reserved Instance is not used (i.e. does not have a running corresponding EC2 instance) the investment made is not valorized. For example, if you reserve a c4.large EC2 instance with default tenancy within US East (N. Virginia) region but for some reason you don't provision an instance with the same type and tenancy, in the same region of the same AWS account or in any other linked AWS accounts available within your AWS Organization, the specified RI is considered unused and you end up paying for a service that you don't use. Note: To receive the right cost optimisation recommendations, you need to enable the Cost Optimisation package for your account and plug in all your AWS Billing accounts into Cloud Conformity using the console.
To determine if you have any unused EC2 Reserved Instances within your AWS account or AWS Organization (available only if you are using Consolidated Billing), perform the following:
Case A: Since AWS EC2 Standard Reserved Instances cannot be canceled, the only way to remove the unneeded EC2 RIs and reclaim their cost is to sell them to other businesses and organizations on Amazon EC2 Reserved Instance Marketplace. To list eligible RIs for sale on the Reserved Instance Marketplace, perform the following:Note 1: Reserved Instances can be sold only after 30 days from the purchase date. Also, there must be at least one month remaining in the term of the EC2 RI that you are listing on Amazon Marketplace.
Case B: Provision corresponding EC2 instances for unused Amazon EC2 Reserved Instances purchased within the current AWS account or within any other member accounts available in your AWS Organization (if you are using one). To launch EC2 instances that match the RIs purchase criteria, perform the following: