# Core requirements

Source: https://developer.avalara.com/products/crossborder/integration-guides/avatax-for-cdit/kjh7825821132417/

Guide: AvaTax Cross-Border (Customs Duty and Import Tax)

# Core requirements

Features required for integration certification.

This section provides an overview of the [Customs Duty and Import Tax](https://developer.avalara.com/certification/avatax/customs-duty-and-import-tax-badge/) badge requirements that you need to meet to become a certified partner. Review this section to help you plan your integration.

This table describes the features that you must include in your integration to receive certification.

Requirement

Use Case

Endpoints/Models

Required/Conditional/Suggested

[Shipping method](/avatax-for-cdit/mtl7682277183172/ "Understand the required shipping method parameter for transactions, including its structure and usage.")

Your integration must include the shipping method associated with the transaction or a line item.

[TransactionParameterModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/TransactionParameterModel/),[TransactionLineParameterModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/TransactionLineParameterModel/)

Required

[Messaging](/avatax-for-cdit/pmc9288878727021/ "Understand the messaging requirements for your integration, including de minimis and sourcing rules.")

Your integration must display appropriate messages for de minimus.

N/A

Required

[Subtotals](/avatax-for-cdit/wrs3667546196372/ "Understand the requirements for displaying Customs Duty and Import Tax subtotals during checkout.")

Your integration must display the appropriate Customs Duty and Import Tax subtotals on checkout when the Seller is Importer of Record.

N/A

Required

[Tax detail storage](/avatax-for-cdit/mys3721688487379/ "Understand how AvaTax stores and separates tax details for cross-border transactions.")

Your integration must include an appropriate level of detail for tax types and tax subtypes. You must save this information in the calling system.

N/A

Required