Feature request: Default end-user profile language per brand

Summary

Allow administrators to configure a default end-user profile language at the brand level, used only when no other language signals are available.

Problem

When a new end user is automatically created via an incoming email, Zendesk assigns the user profile language to English (US) by default.

This occurs even when:

• The account operates entirely outside the US (e.g. UK, NZ, AU)
• The brand is clearly regionalised
• No Help Centre, browser, or user-defined language signal exists

Currently, there is no native way to control or override this behaviour:

• Triggers and automations cannot update the system language/locale field
• The account-level default language acts only as a fallback and is not consistently applied
• Language assignment is not configurable per brand

As a result, organisations experience:

• Incorrect spelling and phrasing in system emails (US vs UK English)
• Inconsistent customer experience
• Unnecessary reliance on API workarounds for a basic configuration need

Proposed solution

Introduce a “Default end-user profile language” setting at the brand level.

Behaviour:

• When a new end user is created and no language can be determined from:
  1. An existing user profile
  2. Help Centre language
  3. Browser language
• Zendesk should assign the brand’s configured default language to the user profile

This setting should:

• Apply only as a final fallback
• Not override an explicitly set user language
• Be configurable independently per brand

Use case

An organisation operates multiple regional brands:

• Brand A: English (UK)
• Brand B: English (US)
• Brand C: French

Customers frequently contact support via email.
When a new customer emails Brand A, their user profile should default to English (UK), ensuring:

• Correct spelling and phrasing in notifications
• Consistent macro and automation behaviour
• Reduced manual or API-based remediation

Impact

Who benefits:

• Global and multi-brand organisations
• Email-first support teams
• Customers outside the US

Business impact:

• Improved localisation accuracy
• Reduced operational overhead
• Fewer custom integrations for basic language control
• Better customer trust and brand consistency

Current workaround

• Custom API scripts or middleware to retroactively update user locales
• Manual correction of user profiles
• Avoiding localisation features entirely and standardising on one language

These approaches add unnecessary complexity and maintenance for a common requirement.

Additional context

Language is a core user attribute, yet administrators currently have no deterministic way to control its default assignment during one of the most common user-creation paths (incoming email).
Aligning this behaviour with brand configuration would significantly improve Zendesk’s localisation model without breaking existing logic.