You can split a single reserved instance (RI) into multiple reserved instances to match smaller pay-as-you-go instances.


Before you split a reserved instance, make sure that the following requirements are met:
  • The reserved instance has been purchased and is in the Active state.
  • There are no ongoing splitting, merging, or change requests.

Background information

For the sake of clarity, reserved instances to be split, merged, or modified are hereinafter referred to as original reserved instances, and the resulting reserved instances are referred to as target reserved instances. You can change the instance type of a reserved instance. The instance family cannot be changed.

After you submit a splitting request:
  • The original reserved instance will enter the Processing state. The reserved instance state will be automatically refreshed after the splitting request has been processed.
  • A request in progress cannot be changed or canceled. If you want to roll back your changes, you must submit another request.
After the reserved instance is split:
  • The target reserved instances will take effect at the top of the hour of the splitting operation. If a target reserved instance matches one or more new pay-as-you-go instances, the billing discount will be applied to the matching pay-as-you-go instances within the same hour.
  • The original reserved instance will be retired at the top of the hour, and its price is updated to USD 0.
  • If the target reserved instances are zonal reserved instances, the type of resources reserved will also be updated automatically.

Assume that you split ecs.g5.2xlarge zonal reserved instance RI1 into two ecs.g5.xlarge zonal reserved instances RI2 and RI3 at 2019-02-26 13:45:00. The term of RI1 ends and the terms of RI2 and RI3 starts at 2019-02-26 13:00:00. Starting from 2019-02-26 13:00:00, the instance type eligible for resource reservation and billing discount will be changed from ecs.g5.2xlarge to ecs.g5.xlarge. If RI2 and RI3 match ecs.g5.xlarge pay-as-you-go instances immediately after RI2 and RI3 take effect, the billing discounts provided by RI2 and RI3 will also be applied to the hourly bills of the pay-as-you-go instances starting from 2019-02-26 13:00:00.

If the original reserved instance fails to be split, the reserved instance will remain valid.


  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Instances & Images > Reserved Instances.
  3. On the Reserved Instances page, find the original reserved instance and click Split in the Actions column.
  4. In the Split Reserved Instance pane that appears, set the names, instance types, and quantities of the target reserved instances.
    Note The total computing power of the target reserved instances must be equal to that of the original reserved instance.
  5. Click OK.