lookup

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name: lookup description: Twilio Lookup v2 phone number intelligence guide. Use when validating phone numbers, detecting line type or carrier, checking fraud risk (SIM swap, SMS pumping), verifying caller identity, or choosing between Lookup data packages. allowed-tools: mcp__twilio__lookup_phone_number, mcp__twilio__check_fraud_risk, Read, Grep, Glob

Lookup v2 Development Skill

Decision-making guide for Twilio Lookup v2 — phone number intelligence, validation, fraud detection, and identity verification. Load this skill when choosing which data packages to use, interpreting Lookup responses, or integrating number intelligence into voice/messaging workflows.

Evidence date: 2026-03-29 | Account: ACxx...xx

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Scope

What Lookup v2 Can Do

• Validate phone numbers (free) — format check, E.164 normalization, country detection
• Identify line type — 12-type classification including fixedVoip vs nonFixedVoip distinction
• Retrieve carrier data — carrier name, MCC, MNC for mobile/VoIP numbers
• CNAM lookup — caller name and type (US numbers only)
• Detect SIM swap — carrier-reported SIM change history (Beta, 10 countries)
• Assess SMS pumping risk — per-number risk score and carrier risk category
• Check number reassignment — whether a US number changed owners since a given date
• Verify identity — match name/address/DOB against carrier records (10 countries)
• Check line status — HLR-based reachability (active/reachable/unreachable/inactive)
• Detect call forwarding — unconditional forwarding status (UK only, Private Beta)
• Combine multiple packages in a single API call — comma-separated fields parameter
• Override line type classification — persist per-account line type override for a number

What Lookup v2 Cannot Do

1. Cannot look up information by name/address — input is always a phone number; you cannot reverse-search "who owns this number" without a number
2. Cannot get CNAM for non-US numbers — returns error 60600 (out of coverage); no international CNAM
3. Cannot detect conditional call forwarding — only unconditional forwarding is detected, and only for UK carriers
4. Cannot guarantee SIM swap data without carrier registration — returns error 60606 until carrier approval is completed
5. Cannot use Reassigned Number outside the US — US-only dataset with monthly update cadence
6. Cannot get real-time SMS pumping scores — scores are statistical models, not live traffic analysis; they change between calls but reflect aggregate patterns
7. Cannot write data — Lookup v2 is read-only (GET only). The one exception is Line Type Override (POST/DELETE)
8. Cannot batch multiple phone numbers in one request — one number per API call; use concurrent requests for bulk lookups
9. Cannot avoid billing on CNAM requests that return no data — billed per request regardless of whether caller name is found
10. Cannot use Phone Number Quality Score or Pre-fill without account provisioning — returns 60606; contact Twilio sales