The regulatory compliance requirements for phone numbers have increased worldwide, affecting developers who use Voice, Fax, or SMS-based applications. Countries are enforcing stricter regulations to prevent fraud, spam, and abuse. To ensure compliance, Twilio provides guidance on its platform, including documentation requirements and mapping processes. Developers must identify the specific requirements for each country where they own or plan to purchase phone numbers, gather necessary documentation, and upload it to the Twilio Console. The process involves verifying identity documents, mapping approved identities to non-compliant numbers, and ensuring compliance with unique requirements for different number types, such as national, local, mobile, or toll-free numbers. Failure to comply may result in suspended or reclaimed phone numbers, making it essential for developers to follow these guidelines to avoid losing their numbers. Twilio collaborates with countries and regulatory agencies to support compliance efforts and advocates for smart changes that preserve value without harming the communications ecosystem.