Modifying Your Reserved Instances
When your computing needs change, you can modify your Reserved Instances and continue to benefit from your capacity reservation.
The following topics guide you through the modification process:
Modification does not change the remaining term of your Reserved Instances; their end dates remain the same. There is no fee, and you do not receive any new bills or invoices. Modification is separate from purchasing and does not affect how you use, purchase, or sell Reserved Instances. You can modify your whole reservation, or just a subset, in one or more of the following ways:
Switch Availability Zones within the same region
Change between EC2-VPC and EC2-Classic
Change the instance size within the same instance type
Availability Zone and network platform modifications are supported for all product platform types (Linux and Windows). Instance type modifications are supported only for the Linux platform types. However, due to licensing differences, it is not possible to change the instance type of RedHat or SUSE Linux Reserved Instances. For more information about RedHat and SUSE pricing, see Amazon EC2 Reserved Instance Pricing.
After modification, the pricing benefit of the Reserved Instances is applied only to instances that match the new parameters. Instances that no longer match the new parameters are charged at the On-Demand rate unless your account has other applicable reservations.