Twilio Lookup is a specialized phone number intelligence and validation API from Twilio, Inc., a public cloud communications platform headquartered in San Francisco, California. It allows developers and risk teams to verify and enrich phone numbers in real time, improving message deliverability, user verification, and fraud detection across global customer bases. en.wikipedia.org
Twilio as a company was founded in 2008 and pioneered the Communications Platform as a Service (CPaaS) model, offering programmable SMS, voice, email, and customer data tools through APIs. Over time it has grown into a broad customer engagement platform used by hundreds of thousands of brands and millions of developers, including many Fortune 500 enterprises, for high-volume, mission‑critical communications. en.wikipedia.org
Lookup focuses specifically on phone number data quality, routing, and risk. With a single API, it can normalize and validate numbers, determine line type (mobile, landline, VoIP, toll‑free, etc.), check carrier and line status, pull caller name where available, and provide advanced risk signals such as reassigned‑number risk, SIM swap, call forwarding, and SMS Pumping Risk Score. These capabilities are exposed as modular data packages like Formatting and Validation, Line Type Intelligence, Identity Match, Reassigned Number, Line Status, Caller Name, SIM Swap, Call Forwarding, and SMS Pumping Risk Score. twilio.com
Positioned at the intersection of communications and fraud prevention, Twilio Lookup is often paired with Twilio Verify, Messaging, and Voice to build adaptive authentication flows and protect against fake accounts, bot activity, and traffic‑pumping schemes. Companies such as Reddit, Resy, Tradier, Persona, and Choco rely on Lookup signals to validate user phone numbers, reduce fraud losses, and optimize messaging costs, helping Twilio maintain a leading position among global CPaaS and identity‑verification vendors. customers.twilio.com