# Configure the Checkout Summary subflow
## Configure a variable for the saved tax identifier
Use the variable to display saved tax identifiers.
To create a variable:
1. Click **Setup** .
2. Type `Flows` in the **Quick Find** field click **Flows**.\
3. Scroll down and click **Subflow - Checkout Summary**. The Flow Builder opens in a separate tab.\
4. Click the **Manager** tab and then click **New Resource**.\
5. Enter the following details:
* Select **Variable** from the **Resource Type** dropdown list.
* **API Name**: Type `Saved_Tax_Identifier` (or any other name with no restrictions).
* Select **Text** from the **Data Type** dropdown list.
* Select the **Available for input** and **Available for output** check boxes.
6. Click **Done**.
{% hint style="warning" %}
You can this variable to display the tax identifier when you[`configure the Checkout Summary subflow`](#configure-the-checkout-summary-subflow).
{% endhint %}
## Configure the Checkout Summary subflow
Use the Checkout Summary subflow to add support for US tax certificates and tax identifiers. To add custom components to the Checkout Summary subflow:
1. From the **Manager** tab, double-click the **Cart to Order Summary** screen.
2. Delete all OOTB components from the subflow except the **Shiping Address** and **Delivery Method** components.
3. Type `drb2b_drUtil` in the **Search components** field and click **drb2b\_drUtil**.\
4. Drag the **drb2b\_drUtil** to where you want it to appear on the Edit Screen.
5. Type `drb2b_drUtil` in the **API Name** field.\
6. Type `drb2b_taxIdentifier` in the **Search components** field and click **drb2b\_taxIdentifier**.\
7. Drag the **drb2b\_taxIdentifier** to where you want it to appear on the Edit Screen.
8. Enter the following details. Be sure to click through all designer attributes to ensure that the default values are registered by Salesforce.
* **API Name**: Type `Tax_Identifier` (or any other name with no restrictions).
* **Cart Id**: Type `{!cartId}`.
* **Selected Tax Identifier**: Type `{!Saved_Tax_Identifier}`.
* Click **Advanced**, select the **Manually assigned variables** check box, and type `{!Saved_Tax_Identifier}` in the **Selected Tax Identifier** field.\
\
9. Type `drb2b_drTermsElement` in the **Search components** field and click **drb2b\_drTermsElement**.\
10. Drag the **drb2b\_drTermsElement** to where you want it to appear on the Edit Screen.
11. Enter the following details. Be sure to click through all designer attributes to ensure that the default values are registered by Salesforce.
* **API Name**: Type `DR_Terms` (or any other name with no restrictions).
* **Auto Initialize**: `{!$GlobalConstant.True}`
* **Cart Id**: Type `{!cartId}`.
* **Bypass Validation**: Type `{!$GlobalConstant.True}` or`{!$GlobalConstant.False}`. By default, this value should be `False`. See [DR terms component](/salesforce-lightning/salesforce-lightning-b2b-commerce-app-1.2.1/extend-the-salesforce-lightning-app/customizing-the-lightning-web-components/components/dr-terms-component.md) for more information.
* **Hide Terms UI:** `{!$GlobalConstant.False}`\
\
12. Click **Done**.
13. Click **Save as**.
14. Enter the name of the custom subflow in the **Flow Label** field (for example, `DR Checkout Summary`) and click **Save**.\
15. Click **Activate**.\
---
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