> This page is for Documentation, version Integration guides (default).
> For other versions, use one of these documentation indexes:
> - Integration guides (default): https://avalara.ferndocs.com/docs/integration-guides/llms.txt
> - Refactor guides: https://avalara.ferndocs.com/docs/refactor-guides/llms.txt
> - Get certified: https://avalara.ferndocs.com/docs/get-certified/llms.txt
> - Agent to Agent (A2A): https://avalara.ferndocs.com/docs/agent-to-agent-a2a/llms.txt
> - AI use cases: https://avalara.ferndocs.com/docs/ai-use-cases/llms.txt
> - API versioning: https://avalara.ferndocs.com/docs/api-versioning/llms.txt

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://avalara.ferndocs.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://avalara.ferndocs.com/_mcp/server.

# Functional review

Congratulations! At this point, you've completed all previous milestones, and now you'll want to review your integration. During your review, make sure that your integration includes all of your necessary elements mentioned in the previous chapters. Specifically, you might want to review the following:

* How you identify customers:

  * Verify that you can pass the customer identifier.

  * Verify that you can exempt a customer.

* How do you identify products/services and associate tax codes?

  * Review what is sent over to AvaTax as the item code and description.

  * Confirm that items can be mapped to AvaTax tax codes in the platform.

* Review your quote-to-cash process, including transaction scenarios along with doc codes:

  * Confirm that the quote-to-cash process specifically calls out the times when the system is reaching out to AvaTax for a tax calculation and when the system is going to record a transaction to AvaTax for further reporting and remittance.

  * Review the testing scenarios:

    * [Multi-merchant scenario](https://developer.avalara.com/marketplace-integration-guide/test-transactions/multi-merchant-scenario)

    * [Direct sale scenario](https://developer.avalara.com/marketplace-integration-guide/test-transactions/direct-sale-scenario)

    * [Tax amount scenario](https://developer.avalara.com/marketplace-integration-guide/Shared/test-transactions/core-sales/tax-amount-scenario)

    * [Discounts scenario](https://developer.avalara.com/marketplace-integration-guide/Shared/test-transactions/core-sales/discounts-scenario)

    * [Entity use code scenario](https://developer.avalara.com/marketplace-integration-guide/Shared/test-transactions/core-sales/entity-use-code-scenario)

    * [Refunds scenario](https://developer.avalara.com/marketplace-integration-guide/Shared/test-transactions/refunds/refunds-scenario)

    * [POS scenario](https://developer.avalara.com/marketplace-integration-guide/Shared/test-transactions/pos/pos-scenario)

* Other considerations

  * Verify that your integration sends the proper HTTP headers (assuming that your integration uses the RESTv2 API).

  * Verify that your integration includes an address validation, filter-by-country option or that you limit address validation requests to only the U.S. and Canada.

  * Verify that your integration uses a reasonable API request ratio during invoicing.

  * Verify that sales invoices or requests that use the `SalesInvoice` document type and that you don't call AvaTax multiple times for the same invoice.

  * Confirm that orders/estimates, use a document type of `SalesOrder`, `PurchaseOrder`, and so on.

> **Note**
>
> Part of the **Marketplace** integration guide. [Open the full "Functional review" milestone on Avalara](https://developer.avalara.com/marketplace-integration-guide/reviewing-your-integration/) to see every page in this section.