---
schema_version: "1"
id: 78ae0ac1c10c92688bd2f44b7ff757e0e4e42095b3fe81fcb13302b433dc3dd6
title: Tax Interface Extension
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/ind/264-0-0/billing_understand_tax_interface_extension.md
canonical_url: https://help.salesforce.com/s/articleView?id=ind.billing_understand_tax_interface_extension.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 2e1d52d485bd65817eb27599e1c1088a0021c2a65997c0f7c455752f8b75f00e
description: Handle tax calculation needs that go beyond standard integrations, capture the right data for audits, and adapt to new requirements through configuration instead of custom code.
products:
  - Revenue Cloud
release: "264"
---
# Tax Interface Extension

Handle tax calculation needs that go beyond standard integrations, capture the right data for audits, and adapt to new requirements through configuration instead of custom code.

### Required Editions

<table class="slds-table slds-table_bordered slds-max-medium-table_stacked slds-m-bottom_small edition"><colgroup><col></colgroup><tbody><tr class=""><td class="slds-cell-wrap" style="vertical-align:top;">Available in: Lightning Experience</td></tr><tr class=""><td class="slds-cell-wrap" style="vertical-align:top;">Available in: <strong>Enterprise</strong>, <strong>Unlimited</strong>, and <strong>Developer</strong> Editions with <a href="https://help.salesforce.com/s/articleView?id=ind.revenue_licenses_areas_and_features.htm&amp;release=264.0.0&amp;type=5">the Revenue Cloud Advanced license or the Revenue Cloud Billing license</a></td></tr></tbody></table>

## Why Do You Need Extended Tax Callout?

Extend your tax callout to solve some of these common challenges with the existing tax interface.

- Your third-party tax provider requires specific data for accurate calculations that isn't included in the standard tax request. For example, a customer's tax identification number or a product's material type.
- You want to capture and store detailed information from the tax provider's response for auditing, reporting, or customer-facing documents. For example, you want to save a specific tax jurisdiction code or an exemption reason on an invoice line.
- Your business needs to adapt to changing tax regulations or expand into new regions that have unique data requirements, and you want to avoid custom code development.

## How Extended Tax Interface Works

Salesforce uses these features to extend the existing tax interface.

- Custom Metadata Type and Mappings: This acts as the central blueprint for your customizations to extend the existing tax interface. You create one main custom metadata type to hold all your mapping definitions. Within your custom metadata type, you create individual records for each custom field you want to add. Each mapping record tells the system which Salesforce field to use, what to name the field in the API call, and whether it's part of the request, the response, or both. See [Custom Metadata Types](https://help.salesforce.com/s/articleView?id=platform.custommetadatatypes_overview.htm&type=5&language=en_US).
- Tax Engine Provider: This is your configured connection to your tax provider. You associate your custom metadata type directly to your tax engine provider. The system extends the tax interface by using the field mappings from the custom metadata type. See [Configure a Tax Engine](https://help.salesforce.com/s/articleView?id=ind.billing_guided_setup_tax_engine.htm&type=5&language=en_US).
- Tax Engine Adapter: The Apex adapter for your tax engine must be able to process the incoming custom fields in the request and add the custom fields to the response. See [Tax Engine Adapter](https://developer.salesforce.com/docs/atlas.en-us.revenue_lifecycle_management_dev_guide.meta/revenue_lifecycle_management_dev_guide/billing_tax_engine_adapter_interface_for_standard_tax.htm).