Enforcing Specific Mobile Phone Number Input Formats

This article provides information on how to manage mobile phone number input formats within the authentication interface. It explains the default normalization behavior and identifies options for implementing strict input validation when users attempt to enter phone numbers in varying local formats.

• Universal Login
• Advanced Customizations for Universal Login (ACUL)

Auth0 automatically handles phone number normalization by transforming various local formats into the industry-standard E.164 format (for example, +61412345678) before storing the data. This process reduces user friction by allowing inputs with or without leading zeros.

If strict enforcement of a specific input format is required, the interface must be customized using one of the following methods:

1. Use Auth0 Forms to build a tailored input field in a form with specific validation logic.

2. Utilize Advanced Customizations for Universal Login to control the input validation and appearance of the login pages.