# Modify an active Capacity Reservation
<a name="capacity-reservations-modify"></a>

If you have an existing Capacity Reservation which isn't a good fit for the workload that needs the capacity, you can modify the instance quantity, instance eligibility (`open` or `targeted`), and end time (`At specific time` or `Manually`). If you specify a new instance quantity that exceeds your remaining On-Demand Instance limit for the selected instance type, the update fails.

The allowed modifications depend on the state of the Capacity Reservation:
+ `assessing` or `scheduled` state — You can modify the tags only.
+ `pending` state — You can't modify the Capacity Reservation in any way.
+ `active` state but still within the commitment duration — You can't decrease the instance count below the committed instance count, or set an end date that is before the committed duration. All other modifications are allowed.
+ `active` state with no commitment duration or elapsed commitment duration — All modifications are allowed.
+ `expired`, `cancelled`, `unsupported`, or `failed` state — You can't modify the Capacity Reservation in any way.

**Considerations**
+ You can't change the instance type, platform, Availability Zone, or tenancy after creation. If you need to modify any of these attributes, we recommend that you cancel the reservation, and then create a new one with the required attributes.
+ If you modify an existing Capacity Reservation by changing the instance eligibility from `targeted` to `open`, any running instances that match the attributes of the Capacity Reservation, have the `CapacityReservationPreference` parameter set to `open`, and are not yet running in a Capacity Reservation, will automatically use the modified Capacity Reservation.
+ To change the instance eligibility, the Capacity Reservation must be completely idle (zero usage) because Amazon EC2 can't modify instance eligibility when instances are running inside the reservation.

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#### [ Console ]

**To modify a Capacity Reservation**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. Choose **Capacity Reservations**, select the Capacity Reservation to modify, and then choose **Edit**.

1. Modify the **Total capacity**, **Capacity Reservation ends**, or **Instance eligibility** options as needed, and choose **Save**.

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#### [ AWS CLI ]

**To modify a Capacity Reservation**  
Use the [modify-capacity-reservation](https://docs.aws.amazon.com/cli/latest/reference/ec2/modify-capacity-reservation.html) command. The following example modifies the specified Capacity Reservation to reserve capacity for eight instances.

```
aws ec2 modify-capacity-reservation \
    --capacity-reservation-id cr-1234567890abcdef0 \
    --instance-count 8
```

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#### [ PowerShell ]

**To modify a Capacity Reservation**  
Use the [Edit-EC2CapacityReservation](https://docs.aws.amazon.com/powershell/latest/reference/items/Edit-EC2CapacityReservation.html) cmdlet. The following example modifies the specified Capacity Reservation to reserve capacity for eight instances.

```
Edit-EC2CapacityReservation `
    -CapacityReservationId cr-1234567890abcdef0 `
    -InstanceCount 8
```

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