# Mapping in ELR

Source: https://developer.avalara.com/products/e-invoicing/integration-guides/elr/rfa1635419604313/

Guide: E-Invoicing and Live Reporting

# Mapping in ELR

Understand how ELR mappings align ERP fields with mandate-specific e-invoicing formats and support UI-based customization.

Each e-invoicing mandate requires specific field structures for documents to be accepted by tax authorities.

To support this, your integration must expose default mandate mappings that show how ERP or business system fields map to the input data format, including any value transformations.

These mappings help users:

-   Validate compliance
-   Speed up implementation
-   Reduce support needs

Your integration must also support customizable mappings. Users must be able to clone, edit, and save their own mappings. This includes:

-   Modifying field names
-   Applying custom logic
-   Adding new UBL fields

Users must be able to perform these actions through the UI, without code changes. This flexibility supports unique ERP setups and evolving regulatory requirements.

## Customizable mandate mappings

Learn how users can customize mandate mappings in ELR.

Users must be able to clone, edit, add, and save mappings.

This ensures that users can make changes and customization based on the specific requirements of their use case and the selected `countryMandate`.

## View mandate mappings

Learn how users can view and manage mandate mappings in ELR.

Describe how your application allows users to access the field-mapping interface between the source system or ERP and the UBL 2.1 fields for each `countryMandate`.

Tip

Business or functional users must be able to manage mapping adjustments without relying on developers. This allows users to make changes quickly without requiring new deployments, system downtime, or dependency on partner release cycles.