# Creating cost categories Cost allocation helps you map and assign your AWS Cloud costs to the correct groups within your organization. To allocate these costs, create cost categories. Cost categories are available only to management accounts of AWS Organizations. When you use billing transfer, each management account (bill transfer and bill source) can configure cost categories only for accounts in its own AWS Organizations.Cost categories are composed of rules. There are two types of rules: 1. Rules to group costs 1. Rules to split costs **Rules to group costs** Define rules to group costs by using one or more of the following dimensions: + Accounts + Cost allocation tags + Charge Type, such as credits and refunds + Service + Region + Usage Type, such as BoxUsage:t2.micro + Billing Entity, such as AWS and AWS Marketplace Rules are evaluated in the order in which they're defined. **Example: Rules to group costs** Your engineering department has projects *Alpha* and *Beta*, and the marketing department has project *Gamma*. All resources are tagged with the project name that they're used for, such as *Project:Alpha*, *Project:Beta*, or *Project:Gamma*. You create a cost category named *Department* to allocate costs to the *Marketing* and *Engineering* departments. For the *Department* cost category, you define your rules as: + Rule 1: If a cost has a cost allocation tag of *Project:Alpha* or *Project:Beta*, then assign the cost to *Department:Engineering*. + Rule 2: If a cost has a cost allocation tag of *Project:Gamma*, then assign the cost to *Department:Marketing*. You can also provide a default name for uncategorized costs. In this example, costs associated with untagged resources should be allocated to the *IT* department + Rule 1: If a cost has a cost allocation tag of *Project:Alpha* or *Project:Beta*, then assign the cost to *Department:Engineering*. + Rule 2: If a cost has a cost allocation tag of *Project:Gamma*, then assign the cost to *Department:Marketing*. + For all other costs, assign it to *Department:IT*. In this example, the cost category name is *Department*. The cost category values are *Engineering*, *Marketing*, and *IT*. **Rules to split costs** Costs that are allocated to one cost category value can be split among others. In this example, if *IT* costs should be split between *Engineering* and *Marketing* departments in a 70:30 ratio, you can define a split charge rule to perform that allocation. When you create your cost category, you can provide additional details such as: + **Effective Date** – Set the start date for your cost category. By default, this date will be set to the current month. If you choose a prior month, your cost category rules are then applied retroactively from that date. + **Tags** – To control access to who can edit this cost category, add a tag to the cost category. You then update your IAM policy to allow or deny access to that cost category. For example, you can add a tag *Role:Administrator* to your cost categories and then update an IAM policy to explicitly allow specific roles access to cost categories that have that tag. Dy default, regular accounts and the management account in AWS Organizations have access to create cost categories. **Tip** To request a backfill of your cost data in your AWS Cost and Usage Report, create a support case. In your support case, specify the report name and the billing period that you want backfilled. For more information, see [Contacting Support](billing-get-answers.md#billing-support). Use the following procedure to create a cost category. After you create a cost category, wait up to 24 hours for your usage records to be updated with the cost category values. **To create a cost category** 1. Sign in to the AWS Management Console and open the AWS Billing and Cost Management console at [https://console.aws.amazon.com/costmanagement/](https://console.aws.amazon.com/costmanagement/). 1. In the navigation pane, choose **Cost Categories**. 1. Choose **Create cost category**. You can use the cost preview panel as reference as you update your rules. 1. Next to **Group your costs**, enter the name of your cost category. Your cost category name must be unique within your account. 1. Use either the **Rule Builder** or **JSON editor** to define your cost categories. For more information about the JSON request syntax, see the [Cost category](https://docs.aws.amazon.com/aws-cost-management/latest/APIReference/API_CostCategory.html) section in the *AWS Billing and Cost Management API Reference* 1. For **Rule builder**, choose **Add rule**. 1. Choose **Rule type**, either **Manually define how to group costs (Regular rule)** or **Automatically group costs by account or tag (Inherit rule)**. 1. For regular rule, choose if your costs meets **all** or **any** of the conditions. 1. Choose a billing **Dimension** from the list. 1. For a regular rule type, you can choose **Accounts**, **Service**, **Charge Type** (for example, *recurring reservation fee*), **Tag key**, **Region**, **Usage Type**, **Cost Category**, or **Billing Entity**. (You can choose **Cost Category** to create hierarchical relationships among your cost categories.) 1. For an inherited value rule type, you can choose **Account** or **Tag key** (Cost allocation tags key). 1. For a regular rule type, choose **Operator** from the dropdown list. Your options are **Is**, **Contains**, **Starts with**, and **Ends with**. **Note** **Contains**, **Starts with**, and **Ends with** are only supported with Accounts and Tag dimensions. If you use these operators with Accounts, the engine evaluates against account name, and not account ID. 1. Choose a filtered value or enter your own value for your **Dimension** in the attribute selector. **Note** The **Account** dimension uses account names, not account IDs for the inherited cost category value. 1. Choose **Add a condition** as needed and repeat steps 9 - 11. 1. For **Group costs together as**, enter a cost category value. 1. Choose **Create rule**. 1. (Optional) Add a default value. It categorizes all unmatched costs to this value. 1. (Optional) To rearrange the rule order, use the arrows or change the number on the top right of each rule. Rules are processed in order. If there are multiple rules that match the line item, then the first rule to match is used to determine that cost category value. 1. (Optional) To remove a rule, select the rule and choose **Delete**. 1. Choose **Next**. 1. (Optional) To split your cost, choose **Add a split charges**. For more information about split charge rules, see [Splitting charges within cost categories](splitcharge-cost-categories.md). 1. Choose **Add a split charge**. 1. Under **Source value**, choose your cost category value. 1. Under **Target values**, choose one or more cost category values you wish to allocate split charges to. 1. Under **Charge allocation method**, choose how you want to allocate your costs. Your choices are **proportional**, **fixed**, and **even split**. 1. For **fixed** charge allocation, enter the percentage amount to allocate each target cost category value. 1. Repeat step 19 as needed. 1. Choose **Next**. 1. (Optional) To add a lookback period for your cost category rules, choose the month from when you want to retroactively apply the rules. 1. (Optional) To add a tag, choose **Add new resource tag** and enter a key and value. 1. Choose **Create cost category**. ## Understanding the cost preview panel The cost preview panel shows you in real time how your costs group together or split apart as you create or update your cost categories rules. The results you see in the cost preview panel is an estimate based on your month-to-date net amortized cost. Here are some things to keep in mind as you use the cost preview panel: + The cost preview results might not be accurate if your rules have complex conditions. For example, containing too many matched values with `Contains`, `Starts With`, `Ends With` operators. For a more precise results, save your rules and check the cost categories details page. + If your rules are too complex or takes too long to calculate in real time, the preview will not show a cost breakdown.