Change	Description	Related documentation
From pay-as-you-go to subscription	System volume: To change the billing method for a system volume, you must first change the billing method of the instance to which it is attached. The volume's billing method updates automatically and cannot be changed separately.	Changing billing method from Pay-as-you-go to Subscription
From pay-as-you-go to subscription		Data volume: You can change the billing method for a pay-as-you-go data volume attached to a subscription instance to subscription. The volume will then expire when the instance expires.	Switching a volume from pay-as-you-go to subscription
From subscription to pay-as-you-go	System volume: To change the billing method for a system volume, you must first change the billing method of the instance to which it is attached. The volume's billing method updates automatically and cannot be changed separately.	Changing billing method from Subscription to Pay-as-you-go
From subscription to pay-as-you-go		Data volume: You can switch a volume from subscription to pay-as-you-go, either individually or together with the instance.	Switching a volume from subscription to pay-as-you-go