Overview - Elastic Compute Service - Alibaba Cloud Documentation Center

You can choose an appropriate billing method based on the Elastic Compute Service (ECS) resource types. This topic describes all billing methods used in ECS, compares the subscription and pay-as-you-go billing methods, and elaborates the cost-effective billing methods such as preemptible instance and savings plans.

Basic billing methods

An ECS instance includes computing resources (vCPUs and memory), an image, and Elastic Block Storage (EBS) devices, and uses one of the following basic billing methods: subscription, pay-as-you-go, or preemptible instance. The following table describes the applicable resources and scenarios of each billing method.

Billing method	Applicable resources	Description	References
Subscription	Computing resources (vCPUs and memory) Image Disk Public bandwidth	A billing method that allows you to use ECS resources only after you pay for them. Subscription is applicable to services that run for 24 hours a day and seven days a week, such as web services. You must pay for subscription resources before you can use them.	Subscription
Pay-as-you-go	Computing resources (vCPUs and memory) Image Disk Public bandwidth Snapshot	A billing method that allows you to use ECS resources and pay for them afterwards. Pay-as-you-go is applicable to applications or services that experience traffic spikes, such as temporary scaling, interim testing, and scientific computing. You can activate and use pay-as-you-go resources before you pay for them. The system generates bills in each billing cycle and deducts corresponding fees from your account.	Pay-as-you-go
Preemptible instance	Computing resources (vCPUs and memory)	Preemptible instances are on-demand instances that you can use before you pay for them. Preemptible instances offer some discounts compared with pay-as-you-go instances and are charged based on the actual usage duration. Prices of preemptible instances fluctuate based on the changes in supply and demand.	Preemptible Instance

Subscription instances, pay-as-you-go instances, and preemptible instances support different features. The following table describes the differences.

Feature	Subscription instance	Pay-as-you-go instance	Preemptible instance
Release instances	To release an instance before it expires, you must first change its billing method from subscription to pay-as-you-go. If you do not renew an instance within the required period of time after the instance expires, the instance is automatically released.	Supported. Release pay-as-you-go instances that you no longer need at the earliest opportunity. If you do not release them, the ECS resources continue to incur charges until the instances are stopped and released due to overdue payments.	Supported. The system may also release an instance when the market price exceeds your bid or when the resources of the instance are insufficient.
Change instance types	Supported.	Supported.	Not supported.
Change bandwidth configurations	Supported.	Supported.	Not supported.
Change billing methods	Supported.	Supported.	Not supported.
Use subscription images from Alibaba Cloud Marketplace	Supported.	Not supported.	Not supported.
Apply for ICP filings for websites that are deployed on ECS instances in the Chinese mainland	Supported. You can apply for ICP filings only for ECS instances that have a subscription period of at least three months. Note Public bandwidth must be purchased for the ECS instances.	Not supported.	Not supported.
Create instances by calling API operations	Supported.	Supported.	Supported.
Use Security Center Basic and CloudMonitor Basic	Supported.	Supported.	Supported.

Cost-effective combinations of billing methods

In addition to subscription, pay-as-you-go and preemptible instance, Alibaba Cloud provides some combinations of billing methods for different ECS resources to reduce costs. You can use a proper combination of billing methods based on your business requirements.

Billing method	Applicable resources	Description	References
Reserved instance	Compute resources (vCPUs and memory) Image	Reserved instances are coupons that can be used to offset the bills of pay-as-you-go instances.	Reserved instances
SCU	Disk Snapshot	Storage capacity units (SCUs) are storage resource plans that can be used to offset the bills of different pay-as-you-go storage resources.	Storage capacity units
Data transfer plan	Public bandwidth	Data transfer plans are effective and economical solutions that can be used to offset the bills of IPv4 data transfers generated by pay-as-you-go instances.	Data Transfer Plan

Switch billing methods

You can switch between billing methods for ECS instances as your business requirements change and evolve. The following table describes the resources whose billing methods can be changed.

Resource	Description	References
Instance	When you change the billing method of ECS instances, the billing methods of their computing resources and system disks are changed to match the billing method of the instance. If your workloads become intermittent or you no longer need the instance, you can change the billing method of an instance from subscription to pay-as-you-go. Then, you need to pay only for what you use and can release the instance at any time. This lets you recover a portion of the subscription costs. Note Alibaba Cloud determines whether you can switch the billing method of an instance based on usage metrics of the instance. Go to the ECS console and check for the button or menu item that is used to change the billing method of an instance. If the button or menu item does not exist, the billing method of the instance cannot be changed. If your workloads shift towards long-term, sustained business, you can change the billing method of an instance from pay-as-you-go to subscription to save on costs in the long run.	Change the billing method of an instance from subscription to pay-as-you-go Change the billing method of an instance from pay-as-you-go to subscription
Cloud disks	You can freely change the billing method of data disks that are attached to subscription instances. However, the billing methods of system disks and data disks on pay-as-you-go instances change together with the billing methods of the instances.	Change the billing method of a disk Change the billing method of an instance from subscription to pay-as-you-go Change the billing method of an instance from pay-as-you-go to subscription
Public bandwidth	You can change the billing method for network usage by upgrading or downgrading instance configurations for instances that have system-assigned public IP addresses.	Change the billing method for network usage