Custom Cost Configuration

The Custom Cost functionality will allow you to create modifications to your AWS bill in order to fulfill multiple use cases. For example:

  • Amortizing RI purchases across hourly usage, thereby accurately billing your internal or external parties for their RI usage (including the RI upfront costs).
  • Creating bills for one or more AWS payees that reflect the stand-alone AWS costs.
  • Modifying usage rates and adding custom charges.
  • The options below determine how custom cost is built. If you change these options, you may need to reload the Detailed Billing Reports.

Configuration Options

Cost Type

Your Custom Cost can be created using either AWS Blended or Unblended Cost as its starting point.

EC2 Reserved Instance Amortization

If desired, you can choose the type of EC2 RI Amortization you’d like to enable.


No RI amortization enabled

Amortize upfront costs by proportional payee hourly usage:
Amortization is added as an incremental charge for every hour an instance is used that matches an RI.

Simple monthly amortization:
Amortization is added as a single charge per RI type at the end of the month

On-demand amortization cap:
Amortization is added to each usage row up until the on-demand cost of the running instance. Any remaining amortization is charged back to the account that purchased the reserved instance.

RI Unsharing

AWS allows Reserved Instances (RIs) to be shared across consolidated billing families. CloudCheckr can “unshared” these to present a custom cost that is more accurate for billing individual accounts so that they are billed for only the actual On Demand usage that occurred.

If you want to enable Unsharing, you should select Unblended Cost from the Cost Type section.


This is the default setting. RI charges will not be unshared, i.e. everything will appear as it does in the AWS bill.

Unshare RIs for all AWS accounts:
RIs will be unshared and any accounts that were previously taking advantage of another’s discounted pricing will now see On Demand pricing.

Changes all usage to on-demand for EC2 / RDS / Redshift / Elasticache, unless the RI is purchased specifically in the payee it is used in. If you do not have credentials added for an account, all RI charges will be changed back to On Demand.

Unshare RIs for selected AWS accounts:
Choose the specific accounts to have RI Unsharing.

Unshare RIs for credentialed AWS accounts:
If you do not have credentials added for an account, the RI charges for that account will not be recalculated and will match the costs within the AWS Detailed Billing Report.


Enforce EC2 Standard Reserved Instance Volume Discounts on Account Families

With this feature enabled, you can adjust any Reserved Instance Volume Discounts to reflect the purchases for any Account Family you have. This will reverse out any RI Volume Discounts that are given for the Consolidated Billing family but may not be due for the Account Family. This feature will give the volume discounts if the Account Family meets the volume discount levels.

For more details, see Amazon EC2 Standard Reserved Instance Volume Discounts on the page


Uncompress Pricing Tiers

AWS creates tiered pricing across consolidated billing families. When this feature is enable, CloudCheckr can uncompress these pricing tiers to present a custom cost that is more accurate for billing individual accounts, so that they will not gain the additional discount that is not intended for them.

NOTE: Once you have configured your Custom Cost, you must reload the DBR for any historical months that you want to be modified by the Custom Cost.


Use Cases

The Default Setup

The Custom Cost default setup is configured to create a “List Cost” where all your payee accounts will be billed as if they are going directly (and independently) to AWS for their services. This means that while an MSP may have hundreds of AWS accounts and can leverage that number to get volume and tiered discounts, they have the flexibility to control if any of those discounts get passed on to their customers.

The default setup is configured like this:

Cost Type:
Unblended (each account shows gets billed for only its actual usage)

EC2 Reserved Instance Amortization:

RI Unsharing:
Enabled (allows only the RI owner to reap benefits of discounted pricing; others pay On Demand)

Enforce EC2 Standard Reserved Instance Volume Discounts on Account Families:

Uncompress Pricing Tiers:


Hourly Amortization

You can use Custom Cost to enable Hourly Amortization so that within your Consolidated Billing Family, any users of an RI will get billed the part of the RI Upfront Cost that is proportional to their usage. The amortized amount will be added to their incremental hourly usage.

The recommended configuration for Hourly Amortization is:

Cost Type:

EC2 Reserved Instance Amortization: On-demand amortization cap. This selection turns on hourly amortization and ensures account will not get billed at a rate higher than On Demand.

RI Unsharing:

Enforce EC2 Standard Reserved Instance Volume Discounts on Account Families:
If you use Account Families and you want the Account Families to earn their own RI Volume discounts, select Enabled. Otherwise, select Disabled.

Uncompress Pricing Tiers: