Overview

As the company decided to expand beyond the US market, inconsistencies in how phone numbers were entered and validated created friction for international users and increased the risk of failed form submissions. To improve user experience and ensure global compatibility, I led an initiative to standardize all phone number fields to comply with the E.164 international telephone numbering standard.

Problem

Our existing phone number inputs assumed US-based formatting rules. This created several issues:

• International users were unable to input valid phone numbers in the correct format.
• Backend systems struggled with inconsistent number formats, leading to data integrity problems.
• Support tickets related to “invalid phone number” errors were increasing in non-US markets.

With the company's plans to expand globally, this inconsistency was a risk to both user acquisition and operational efficiency.

Goal

• Ensure that all phone number inputs across our apps accept and validate numbers from any country.
• Reduce form submission errors for international users.
• Maintain backend data integrity for phone numbers.

Research & Discovery

I researched international numbering standards and identified the E.164 format, used by the Public Switched Telephone Network.

Key findings:

• Each phone number must include a country code, area code, and subscriber number.