Reserved instances are independently billed coupons that can be used to offset the bills of pay-as-you-go Elastic Compute Service (ECS) instances to provide billing discounts. This topic describes the payment options and billing rules of reserved instances.

Payment options

Reserved instances cannot be used alone and must be used in conjunction with pay-as-you-go instances. Reserved instances can be matched to pay-as-you-go instances to cover charges for computing resources, not charges for network and storage resources, based on the computing power of the reserved instances. For more information, see Overview.

Reserved instances support the following payment options:
  • All Upfront: Full payment is required upfront at the time of purchase with no other costs or additional hourly charges incurred throughout the term.
  • Partial Upfront: Partial payment (about 50% of the full amount) is required upfront at the time of purchase and the remainder is paid at a discounted hourly rate throughout the term.
  • No Upfront: No upfront payment is required at the time of purchase. You are billed a discounted hourly rate every hour throughout the term.
    Note Your ECS usage determines whether you can use the No Upfront payment option.

Partial Upfront and No Upfront reserved instances are billed in 1-second increments. Their bills are generated hourly and paid monthly. For more information, see the Pricing tab on the Elastic Compute Service product page. If the payable amount reaches USD 1,000, the amount is automatically deducted from your account balance. Any amount less than USD 1,000 is added to the monthly bill.

Billing rules

A reserved instance takes effect immediately after it is purchased, and then matches eligible pay-as-you-go instances on an hourly basis to offset the bills of the pay-as-you-go instances. You are charged based on the payment option that you selected regardless of whether the reserved instance is matched to pay-as-you-go instances. The All Upfront option is the most cost-effective.

A reserved instance takes effect and is billed starting on the hour of your purchase. The reserved instance expires at 24:00:00 on the expiration day. For example, if you purchase a reserved instance with a one-year term at 22:45:00 on May 1, 2020, the reserved instance takes effect and is billed starting from 22:00:00 on May 1, 2020. The reserved instance expires at 24:00:00 on May 2, 2021. If you purchase a reserved instance and you already have pay-as-you-go instances that match the attributes of the reserved instance, the reserved instance is applied to offset the bills generated for the pay-as-you-go instances starting from the hour of 22:00 to 23:00 on May 1, 2020 until the reserved instance expires.


You can renew reserved instances for one month, one year, or three years.
Note After reserved instances are split or merged or have their scopes changed, new reserved instances are generated and can be renewed.