High-level description of the requirement

Objective

To enable the creation and processing of EN 16931-1 conformant electronic invoices in multiple languages, ensuring that language preferences can be set at different levels of the invoice structure. This flexibility will support international business transactions and enhance clarity for parties speaking different languages.

Requirement Overview

The eInvoicing system must support the ability to define languages at the following levels:

1. Invoice Top Level – A single language applicable to the entire invoice document.
2. Free Text Elements Level – Language-specific settings for all free text fields, including but not limited to:
   1. Notes
   2. Item Descriptions
3. Address Group Level – Language-specific settings for all postal address groups, including but not limited to:
   1. Buyer Postal Address
   2. Seller Postal Address
   3. Deliver To Address

Detailed Requirements

1. Invoice Top Level Language
   1. The system must allow setting a default language at the top level of the invoice. This language will apply to all textual elements unless overridden at lower levels.

1. Free Text Elements Language
   1. The system must support the ability to assign different languages to free text elements such as Notes and Item Descriptions within the invoice.
   2. Each free text element should have an optional field to specify the language of that content.
   3. If no language is specified for a free text element, the system should default to the top-level language of the invoice.

1. Postal Address Group Language
   1. The system must enable the setting of distinct languages for the Buyer and Seller postal address groups, allowing international postal addresses to be provided in the language that best serves the recipient.
   2. Language specification at the Address Group level should take precedence over any top-level or invoice-wide language settings.
   3. The system should allow the parties to input their respective addresses in their preferred languages and formats.

Mapping tested with UBL 2.5 draft of 2025-07-25

Is it sufficient to have:

/Invoice/cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cbc:StreetName/@languageLocaleID

and

/Invoice/cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cbc:StreetName/@languageID

Or are language IDs at cac:PostalAddress desired/required?

Are there more changes desired/required to please the EU extension requirement?