Purchasing Amazon EC2 Reserved Instances

1. Log in to the AWS Management Console.
2. In the Amazon Web Services menu choose “EC2”.
3. In the left navigation pane, choose “Reserved Instances”.
4. Choose “Purchase Reserved Instances”.
5. Select your Reserved Instance type, platform, payment option, instance type, offering class, and term length. Optionally, check the "Only show offerings that reserve capacity" box to select an Availability Zone, if you want to reserve capacity.
6. Adjust the quantity of instances to purchase and ensure you are comfortable with the price quoted.
7. Confirm your purchase.

Important notes about purchases

• If your needs change, you can modify or exchange reserved instances, or list eligible Standard Reserved Instances for sale on the Reserved Instance Marketplace. 
• You can purchase up to 20 Reserved Instances per Availability Zone each month. If you need additional Reserved Instances, complete this form.
• Purchases of Reserved Instances are non-refundable.
• If you purchase a Reserved Instance from a third- party seller, we will share your city, state, and zip code with the seller for tax purposes. If you don’t wish to purchase from a 3rd party seller, please make sure to select a Reserved Instance with “AWS” listed as the seller in the console purchasing screen.

Customers using both Reserved and On-Demand instances will have Reserved Instance rates applied first to minimize costs. You pay the low hourly usage fee for every hour in your Reserved Instance term (which means you’re charged the hourly fee regardless of whether any usage has occurred during an hour). When your total quantity of running instances during a given hour exceeds the number of applicable Reserved Instances you own, you will be charged the On-Demand rate.

For example, if you own three Reserved Instances with the same instance attributes and region (or Availability Zone if applicable), the billing system checks each hour to see how many total instances you have running that match those parameters. If it is three or less, you will be charged the Reserved Instance rate for each matching instance running that hour. If more than three are running, you will be charged the On-Demand rate for the additional instances.