> For the complete documentation index, see [llms.txt](https://developer.esw.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.esw.com/customs-catalog-api/customs-catalog-api/overview.md).

# Overview

Share product catalog data with ESW to calculate duties and taxes at checkout and support customs compliance.

{% hint style="danger" icon="thumbtack-angle" %}

#### [**EU Product Identifier requirement**](/customs-catalog-api/customs-catalog-api/concepts/product.md#optional-product-identifier-fields) **(effective 1 November 2026)**

The EU Product Identifier requirement becomes mandatory for EU imports from 1 November 2026. Where a product has one, ESW uses its `EAN` or `UPC` as the Standardised Manufacturer Product Identifier.

You do not need to create an `EAN` or `UPC` for a product that genuinely does not have one. Leave `ean` and `upc` empty for those products.
{% endhint %}

The Customs Catalog API ingests retailer product catalogs, classifies items using Harmonized System (HS) codes, and serves per-product duty and VAT rates to downstream checkout and shipment systems.

Use the Customs Catalog API to share your product catalog with ESW. ESW uses this data to calculate duties and taxes at checkout. It also supports customs compliance for cross-border shipments.

{% hint style="info" %}
For catalog file integration, see [catalog file](/integrations/integrations/catalog-file-integration.md) to send your product master data to ESW.
{% endhint %}

### What this API does

<table data-card-size="large" data-view="cards"><thead><tr><th></th><th data-hidden>Description</th><th data-hidden data-card-cover data-type="image">Cover image</th><th data-hidden data-card-cover-dark data-type="image">Cover image (dark)</th></tr></thead><tbody><tr><td>Catalog Ingestion</td><td>Accept catalogs via JSON API or file upload. Validate fields.</td><td><a href="https://3739774233-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJWssSKqn34oo0GTi1dVW%2Fuploads%2FBBAZkA1k6QVBzcpSGWjF%2FPictogram-09.svg?alt=media&amp;token=8e30b775-b978-443f-a2d7-85ee98b2a826">Pictogram-09.svg</a></td><td><a href="https://3739774233-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJWssSKqn34oo0GTi1dVW%2Fuploads%2FH31xlsPt6WoyOlNIOku7%2FPictogram-10.svg?alt=media&amp;token=bdb58f15-dce6-4124-982c-f4df55fda26e">Pictogram-10.svg</a></td></tr><tr><td>HS Classification</td><td>Map each product to a Harmonized System tariff code. </td><td><a href="https://3739774233-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJWssSKqn34oo0GTi1dVW%2Fuploads%2FuOCUodLR5iRE3uOFNzA1%2FPictogram-11.svg?alt=media&amp;token=81e9a10f-906b-46e5-8bb1-b85b47f43e48">Pictogram-11.svg</a></td><td><a href="https://3739774233-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJWssSKqn34oo0GTi1dVW%2Fuploads%2FvApyNYuQWCENoFRDtvrO%2FPictogram-12.svg?alt=media&amp;token=a901b921-80f6-4cf4-9648-c9ac492dfa54">Pictogram-12.svg</a></td></tr></tbody></table>

### Catalog basics

{% tabs %}
{% tab title="What’s in a catalog" %}
A catalog is the product dataset you share with ESW.

Each record usually represents one product or variant.

Typical fields include:

* Product code
* Name
* Description
* Material
* Country of origin
* HS code
* HS code region

You can also send category, size, gender, age group, product URLs, image URLs, and extra identifiers.
{% endtab %}

{% tab title="Why it matters" %}
Catalog data drives duty and tax calculation at checkout.

It also supports classification and customs compliance.

Good catalog data helps you:

* Improve duty and VAT accuracy
* Reduce invalid or unclassified products
* Avoid customs delays
* Keep shopper pricing consistent
  {% endtab %}

{% tab title="How it works" %}
The Customs Catalog API processes uploads asynchronously.

1. Send a full catalog during onboarding.
2. Send only new or changed items after that.
3. ESW validates the payload and accepts the request.
4. Products are processed, classified, and enriched.
5. Invalid products are surfaced for review and reprocessing.

Processing continues after the request is accepted.
{% endtab %}
{% endtabs %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://developer.esw.com/customs-catalog-api/customs-catalog-api/overview.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.