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Reserved Instance quotas - Amazon Elastic Compute Cloud

Reserved Instance quotas

There is a limit to the number of Reserved Instances that you can purchase per month, as follows:

  • For each Region, you can purchase 20 regional Reserved Instances per month.

  • Plus, for each Availability Zone, you can purchase an additional 20 zonal Reserved Instances per month.

For example, in a Region with three Availability Zones, the limit is 80 Reserved Instances per month: 20 regional Reserved Instances for the Region plus 20 zonal Reserved Instances for each of the three Availability Zones (20*3=60).

A regional Reserved Instance applies a discount to a running On-Demand Instance. The default On-Demand Instance limit is 20. You cannot exceed your running On-Demand Instance limit by purchasing regional Reserved Instances. For example, if you already have 20 running On-Demand Instances, and you purchase 20 regional Reserved Instances, the 20 regional Reserved Instances are used to apply a discount to the 20 running On-Demand Instances. If you purchase more regional Reserved Instances, you will not be able to launch more instances because you have reached your On-Demand Instance limit.

Before purchasing regional Reserved Instances, make sure your On-Demand Instance limit matches or exceeds the number of regional Reserved Instances you intend to own. If required, make sure you request an increase to your On-Demand Instance limit before purchasing more regional Reserved Instances.

A zonal Reserved Instance—a Reserved Instance that is purchased for a specific Availability Zone— provides capacity reservation as well as a discount. You can exceed your running On-Demand Instance limit by purchasing zonal Reserved Instances. For example, if you already have 20 running On-Demand Instances, and you purchase 20 zonal Reserved Instances, you can launch a further 20 On-Demand Instances that match the specifications of your zonal Reserved Instances, giving you a total of 40 running instances.

The Amazon EC2 console provides quota information. For more information, see View your current limits.