Overview

WAF supports yearly/monthly (prepaid) and pay-per-use (postpaid) billing. For cloud WAF, both billing modes are supported. For dedicated WAF instances, only pay-per-use billing is supported.

Yearly/monthly billing: The longer you use, the more you save. You need to pay the bill for the required duration.
Pay-per-use billing: This billing mode allows you to make a subscription or unsubscription at any time.
- For a pay-per-use cloud WAF instance, you are billed for the number of added domain names, number of customized rules, and number of forwarded requests.
- For a pay-per-use dedicated WAF instance, you are billed for the required duration (accurate to second), which starts when the instance is created and ends when the instance is deleted.

To use ELB-access cloud WAF, you need to submit a service ticket to enable it for you first. ELB-access cloud WAF is available in some regions. For details, see Functions.
If you have purchased cloud WAF (standard, professional, or platinum edition), CNAME and ELB access methods share the domain name, bandwidth, and rule extension packages you have purchased.

**Table 1** Differences between billing modes
Billing Mode	Yearly/Monthly	Pay-per-use
Payment Method	Prepaid	Postpaid
Metering Period	Billed by the purchase period specified in the order	Cloud mode: The bills for protected domain names are settled on an hourly basis. The bills for custom protection rules are settled every 24 hours. The bills for requests are settled monthly. Dedicated mode: Instances are billed by the second, and bills are settled on an hourly basis.
Billing Item	Cloud mode: service edition, domain name, QPS, and rule expansion packages	Cloud mode: the number of domain names, the number of custom rules, and the number of requests Dedicated mode: the number of instances
Changing the Billing Mode	This billing mode cannot be directly switched to pay-per-use billing mode. You can purchase a pay-per-use cloud WAF instance after the yearly/monthly WAF instance expires or has been unsubscribed from.	This billing mode cannot be directly switched to pay-per-use billing mode. You can disable pay-per-use billing and purchase a yearly/monthly WAF instance.
Application Scenario	This billing mode is cost-effective and suitable when the duration of resource usage is predictable. The yearly/monthly mode is recommended for long-term users.	This mode is ideal when you want more flexibility and control on WAF usage.