AWS: Cost and Billing

These Frequently Asked Questions (FAQs) answer the most common questions we get asked about AWS and CloudCheckr billing.

Question: What are the reasons why CloudCheckr shows different costs than AWS Cost Explorer?

Answer:

In the General FAQ, we briefly identified the reasons why the AWS Cost Explorer and CloudCheckr show different costs:

  • cost rates
  • RI unsharing
  • differences between DBR to CUR
  • amortization
  • application of credits
  • AWS Marketplace charges

This FAQ examines these reasons in more detail.

AWS and CloudCheckr use blended and unblended cost rates in their calculations, but CloudCheckr also calculates a list cost rate.

Here's how each rate compares:

Type

Cost Calculations

Outcomes

Benefit(s)

Blended

Averages on-demand and reserved pricing using a common usage rate for shared resources in a consolidated billing family.

Does not factor in support costs.

RI purchaser may see rates higher than the RI rate while On Demand users may see rates lower than the On Demand rates.

Good way to determine the average costs across a consolidated bill

Unblended

Account that purchased the RI is responsible for all RI costs.

Accounts that consume the RI(s) but did not purchase them will have lower-than-actual costs.

When an account other than the purchasing account uses the RI, those RI hours show up as a zero cost in that account.

Payees who shared RIs and benefited from the lower pricing tiers of other payees in the consolidated billing family will have a lower bill.

Helps individual payees within the consolidated billing family

List

Reverses unintended payee discounts on EC2 RIs, RDS RIs, and tiered pricing.

Mimics AWS cost for each payee as if they were a standalone account—plus or minus additional custom discounts or charges issued by the the owner of the consolidated billing family.

Helps MSPs or resellers

Caveat on Unblended Costs:

The cost calculation, outcome, and benefits described in the table describe how blended costs will work after June 17, 2019.

For details on how unblended costs work today and up to June 16, 2019, see the Transition from DBR to CUR topic.

Caveat: Amortization values will be based on the type of amortization that the owner of the payer account selected.
The amortization reflected in a customer's final AWS bill may not match what they see in their CloudCheckr invoice. In AWS, the amortization costs only impact the payer account since it is seen as the primary account in the consolidated billing family. In CloudCheckr, however, you can configure the amortization so that payees get charged based on their usage hours. This is known as Proportional Payee Amortization.

For example, let's say a payer buys 1,000 RIs with an upfront amortization fee of $1,000. 500 of those RIs run across the entire consolidated billing family—which works out to $2 per instance. Payee A is only using 100 of those RIs. If a CloudCheckr customer applies Proportional Payee Amortization, Payee A's cost would be $200—which rmirrors their exact usage.

Costs for RI usage in the final AWS and CloudCheckr bills may not match because our application allows RI unsharing.

RI unsharing is a custom cost that enables CloudCheckr customers to filter the RI usage by account(s) that used the RI. By enabling RI usnsharing, payers can bill payee accounts on their actual on-demand usage and remove any confusion surrounding shared RIs.

Click the buttons to see how AWS calculates RI costs in the DBR and CUR today and how it plans to correct these inconsistencies moving forward.

The AWS Cost Explorer uses the CUR as its source for cost calculations while CloudCheckr uses the DBR. If all RIs are used in the account that purchased the RI, you will not see any variations in cost between the CUR and DBR.

Once payees start to share RIs, you may see disparities in the unblended cost rate for line items because:
  • in the CUR, all RI costs stay in the account that purchased the RI but the accounts that used the RI are not charged for using that RI
  • in the DBR, the RI costs are applied to the account(s) that used the RI—not the account that purchased the RI

In the end, the grand totals for the DBR and CUR should match and you can dismiss any disparities as rounding errors. See the Transition from DBR to CUR topic for an example of two use cases where those disparities may be more significant.

Starting June 17, AWS is changing the DBR so that it uses the same methodology for sharing RI costs as the CUR—ensuring that the DBR and the CUR report the same costs for each account. Review the Changes to the Detailed Billing Report topic in AWS for more information.

A complication with AWS billing is the way it distributes AWS credits. When a payee receives an AWS credit, AWS applies that credit across the entire consolidated billing family. AWS uses an algorithm to allocate a percentage of the credit to each payee—not just to the payee who earned it. In addition, how the algorithm calculates these percentages is a bit of a mystery.

For example, a payee receives a $50 credit for completing a survey and enters a code into AWS with the expectation that AWS will apply the credit to their account. However, AWS distributes that credit across all payee accounts in the consolidated billing family. The result is that payees who did not earn the credit benefit unintentionally while the original payee does not receive their fair share.

Fortunately, CloudCheckr allows you to rectify these credit allocations by hiding credits from payees and/or assigning credits to selected payees only. The result is that the credits in your AWS bill may not match what you see in your CloudCheckr invoice, but the allocation will be an accurate reflection of which payee earned the credit.

When the DBR was the primary billing method for AWS, customers would receive two separate DBR files—one for infrastructure files (the DBR) and another for software usage (the Markeetplace DBR). Now that the AWS Cost Explorer is using the CUR as its primary billing method, you can see your AWS Marketplace costs in your monthly AWS bill. While this improvement allows you to better manage your AWS Marketplace products and more effectively compare your SaaS and cloud costs in one bill, there is a burden on the customer to weed through all of the AWS Marketplace jargon and make sense of all the charges.

CloudCheckr, however, provides a Spend Analysis report that allows you to uderstand these charges and see how they relate to your entire family of AWS costs.

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