Can I use promotional credits to purchase Reserved Instances (RIs)?
Promotional credits can't be applied to upfront costs for Partial Upfront RIs, All Upfront RIs, or Savings Plans.
However, the hourly rates that you pay for running instances can be covered by your credits when you have Partial Upfront RIs, No Upfront RIs, or Savings Plans.
Check that your credits apply to usage for the service in the Credits pane of the AWS Billing and Cost Management console.
Note: Credits might be applied differently if your account is in an organization. For more information, see How is the pricing benefit of a Reserved Instance applied across an organization's consolidated bill?
Redeem your AWS promotional credit
Amazon EC2 Reserved Instances