Amazon EC2 Reserved Instances

Reserved Instances provide you with a significant discount (up to 75%) compared to On-Demand instance pricing. You have the flexibility to change families, OS types, and tenancies while benefitting from Reserved Instance pricing when you use Convertible Reserved Instances.

Reserved Instances can provide a capacity reservation, offering additional confidence in your ability to launch the number of instances you have reserved when you need them.

EC2 Reserved Instances provide a discounted hourly rate and an optional capacity reservation for EC2 instances. AWS Billing automatically applies your Reserved Instances discounts when attributes of EC2 instance usage match attributes of an active Reserved Instance.

If an Availability Zone is specified, EC2 reserves capacity matching the attributes of the Reserved Instance. The capacity reservation of a Reserved Instance is automatically utilized by running instances matching these attributes.

With Reserved Instances, you can choose the type that best fits your applications needs.

• Standard Reserved Instances: These provide the most significant discount (up to 75% off On-Demand) and are best suited for steady-state usage. 
• Convertible Reserved Instances: These provide a discount (up to 45% off On-Demand) and the capability to change the attributes of the Reserved Instance as long as the exchange results in the creation of Reserved Instances of equal or greater value. Like Standard Reserved Instances, Convertible Reserved Instances are best suited for steady-state usage. 
• Scheduled Reserved Instances: These are available to launch within the time windows you reserve. This option allows you to match your capacity reservation to a predictable recurring schedule that only requires a fraction of a day, a week, or a month.
  

The following summarizes features of all Reserved Instances.

• Provide a significant discount compared to running instances On-Demand.
• Can apply to usage across all Availability Zones in an AWS region, or can provide a capacity reservation when assigned to a specific Availability Zone.
• Are offered under three upfront payment options to provide you with payment flexibility at the point of purchase.
• Can be shared between multiple accounts within a consolidated billing family.

The following table summarizes the differences between Standard and Convertible Reserved Instances.

• Offering class: There are two classes of Reserved Instances: Convertible and Standard. Convertible Reserved Instances can be exchanged for different Convertible Reserved Instances of equal or greater value. 
• Term: AWS offers Standard Reserved Instances for 1-year or 3-year terms. Reserved Instance Marketplace sellers also offer Reserved Instances often with shorter terms. AWS offers Convertible Reserved Instances for 3-year terms.
• Payment option: You can choose between three payment options: All Upfront, Partial Upfront, and No Upfront. If you choose the Partial or No Upfront payment option, the remaining balance will be due in monthly increments over the term.
  

When the attributes of the Reserved Instance match the attributes of a used instance, the discount of the Reserved Instance is applied and the capacity reservation is utilized. These attributes are:

• Instance type: Instance types comprise varying combinations of CPU, memory, storage, and networking capacity. For example, m3.xlarge.
• Platform description: Reserved Instances can be purchased for Amazon EC2 instances running Linux/UNIX, SUSE Linux, Red Hat Enterprise Linux, Microsoft Windows Server, and Microsoft SQL Server platforms.
• Tenancy: If you are using instances with a default tenancy, purchase default tenancy Reserved Instances. If you are using dedicated instances, purchase Reserved Instances with a tenancy of dedicated.
• Availability Zone (optional): By selecting an Availability Zone, the Reserved Instance you purchase will provide a capacity reservation and a discount for the use of instances in the selected Availability Zone. When an Availability Zone isn’t specified, the Reserved Instance discount will apply to a running instance in the region that matches the other attributes.
  

Visit the Amazon EC2 Pricing page to view Reserved Instance pricing.
If you purchase a large number of Reserved Instances in an AWS region, you will automatically receive discounts on your upfront fees and hourly fees for future purchases of Reserved Instances in that AWS region.
Reserved Instances are sold by third-party sellers on the Reserved Instance Marketplace, who occasionally offer even deeper discounts at shorter terms.

Reserved Instance Marketplace allows other AWS customers to list their Standard Reserved Instances for sale. Third-party Standard Reserved Instances are no different from the Standard Reserved Instances purchased directly from AWS except they are often listed at lower prices and shorter terms. To learn more about how to buy a Standard Reserved Instance from AWS or from third-party sellers, visit the Amazon EC2 Reserved Instances Getting Started page.

To learn more about selling your Reserved Instances on the Reserved Instance Marketplace, visit the Amazon EC2 Reserved Instance Marketplace page.

Visit the Amazon EC2 Reserved Instance Getting Started page to learn more about how to purchase the right Amazon EC2 Reserved Instance.