You can use storage capacity units (SCUs) to offset the pay-as-you-go bills of storage resources such as disks, Object Storage Service (OSS), Apsara File Storage NAS (NAS), and snapshots. SCUs use the subscription billing method. The all upfront payment option is supported.

Billing method

SCUs use the subscription billing method, and are billed based on their capacity and validity period. For more information about pricing, see the Pricing tab on the Storage Capacity Unit page.

  • SCU capacity: For the capacity specifications that SCUs support, see Overview.
  • Validity period: You can subscribe to an SCU for a period of 1 month, 2 months, 3 months, 6 months, 12 months, 3 years, or 5 years. If you use an annual or multi-year subscription, you can receive some discounts.

SCUs support only the all upfront payment option. You must make a full payment at purchase.

Sum = Validity period × SCU capacity × SCU unit price.Unit: USD.

Usage rules

After you purchase an SCU, the SCU automatically matches qualified pay-as-you-go storage resources to offset their bills before the SCU expires. When the used capacity exceeds the SCU capacity, the excess capacity is billed on a pay-as-you-go basis.

The amount of storage capacity that an SCU can offset varies based on the types of resources to which the SCU is applied. For more information, see Usage rules.


After an SCU expires, you cannot use it to offset the bills of pay-as-you-go storage resources. If you have no other SCUs within the same region, those pay-as-you-go resources are billed on a pay-as-you-go basis.