If you no longer need an RDS Custom instance, you can unsubscribe from or release the instance to prevent further charges.
Prerequisites
The status of the stopped instance is Paused.
Important notes
The procedure for unsubscribing from subscription and pay-as-you-go RDS Custom instances is the same. After you start the procedure:
For subscription instances, Alibaba Cloud reclaims the resources and provides a refund based on the unsubscribe rules.
For pay-as-you-go instances, the instance is released. No refund is provided because you are billed for resources as you use them.
Procedure
Log on to the RDS console. In the navigation pane on the left, click RDS Custom > Instances. Then, select a region.
Unsubscribe from or release instances.
To release (unsubscribe from) a single instance: In the Actions column of the target instance, click .

You can also click on the Basic Information page.
To unsubscribe from or release multiple instances: Select the instances to release, and at the bottom of the page, click Unsubscribe.

In the dialog box that appears, click OK.
Related operations
For subscription RDS Custom instances, you can also unsubscribe in the Expenses and Costs console.