Comparison of Billing Modes

There are yearly/monthly, pay-per-use, and serverless billing modes. Each one has different advantages and disadvantages.

Yearly/Monthly is a prepaid billing mode. You pay in advance for a subscription term, and in exchange, you get a discounted rate. The longer the subscription term, the bigger the discount. Yearly/Monthly billing is a good option for long-term, stable services.
Pay-per-use is a postpaid billing mode. You pay as you go and just pay for what you use. The DB instance usage is calculated by the second but billed every hour. Pay-per-use billing is a good option for scenarios where there are sudden traffic bursts, such as e-commerce promotions.
Serverless: The instance capacities automatically change based on application requirements. You can start using the DB instance first and then pay as you go.

**Table 1** Differences between billing modes
Billing Mode	Yearly/Monthly	Pay-per-use	Serverless
Payment	Prepaid Billed by the subscription term you purchase	Postpaid Billed for what you use	Postpaid Billed for what you use
Billed Usage Period	Billed by the subscription term you purchase	Calculated by the second but billed every hour	Calculated by the second but billed every hour
Billed Item	Instance specifications (vCPUs and memory), storage space, backup space, EIP, and monitoring by seconds NOTE: If a DB instance is deleted, its automated backups will also be deleted and you will no longer be billed for them. Manual backups are retained and generate additional costs. You need to manual delete manual backups.	Instance specifications (vCPUs and memory), storage space, backup space, EIP, and monitoring by seconds NOTE: If a DB instance is deleted, its automated backups will also be deleted and you will no longer be billed for them. Manual backups are retained and generate additional costs. You need to manual delete manual backups.	Instance specifications (vCPUs and memory), storage space, backup space, EIP, and monitoring by seconds NOTE: If a DB instance is deleted, its automated backups will also be deleted and you will no longer be billed for them. Manual backups are retained and generate additional costs. You need to manual delete manual backups.
Changing the Billing Mode	Yearly/Monthly can be changed to pay-per-use. The change takes effect only after the yearly/monthly subscription expires. Changing the Billing Mode from Yearly/Monthly to Pay-per-Use	Pay-per-use can be changed to yearly/monthly. Changing the Billing Mode from Pay-per-Use to Yearly/Monthly	N/A
Changing the Specifications	Supported	Supported	Supported
Application Scenario	Recommended for resources expected to be in use long-term. A cost-effective option for scenarios where the resource usage duration is predictable.	Recommended when the resource demands are likely to fluctuate and you want more flexibility.	The instance capacities automatically change based on application requirements.