Twilio Lookup
Phone number lookup API for validation, line type and fraud signals
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Pricing
Freemium
Free trial
Yes
API
Yes
Company
Twilio
Platforms
What is Twilio Lookup?
Twilio Lookup is a phone number intelligence API. It validates number formats and returns details such as carrier, line type and line status, so apps can confirm a number is real and reachable before sending SMS or placing calls.
Lookup runs in the background during signup, login or checkout. It uses mobile-identity signals to separate real users from suspicious ones, so teams can add friction such as extra verification only for risky sign-ups. Twilio lists fake account creation, bot attacks, SIM swap, promo abuse and SMS pumping fraud among the threats it helps catch.
The product sits in Twilio's Authentication & Identity line next to Verify. It suits developers and fraud teams who already send messages through Twilio, as well as any business that wants better deliverability and fewer messages sent to invalid numbers. Basic format validation is described as free to use, and Twilio offers a free trial with no credit card required.
Key features
- Phone number format validation
- Carrier and provider lookup
- Line type and line status detection
- SIM swap fraud signals
- SMS pumping and bot attack prevention
- Risk signals for adaptive authentication
- Active consent information for contact numbers
Use cases
Who it's for
Cleaning contact data before messaging
Check format, line type and status so SMS and calls go only to reachable numbers, which cuts delivery costs.
Blocking fake sign-ups
Look up numbers at registration to flag suspicious ones and stop fake account creation and promo abuse.
Preventing SIM swap account takeover
Use mobile signals to spot risky numbers before sending verification codes or allowing sensitive actions.
Adaptive authentication
Add extra verification steps only for users who present a risk, leaving trusted users with a smoother flow.
Twilio Lookup pricing
From the vendor's site, checked Nov 14, 2026. Prices change — confirm on their pricing page.
The vendor does not publish plan details.
How Twilio Lookup compares
- Twilio Lookup has a free plan; none of the 4 alternatives below do.
| Tool | Starts at | Free plan | Free trial | API | Open source | |
|---|---|---|---|---|---|---|
| TTwilio Lookup | — | — | ||||
H HLR Lookups | — | — | — | Twilio Lookup vs HLR Lookups | ||
| TTelnyx Number Lookup | — | — | — | — | Twilio Lookup vs Telnyx Number Lookup | |
V Vonage | — | — | — | Twilio Lookup vs Vonage | ||
S Sinch | — | — | — | Twilio Lookup vs Sinch |
The closest alternatives in our directory by category. “Starts at” is the cheapest paid plan per month, as each vendor lists it.
Pros and cons
Strengths
- Basic number format validation is described as free to use
- Free trial with no credit card required
- One API covers deliverability and fraud signals
- Works with Twilio Verify, SMS and Voice products
Limitations
- Developer API only, with no standalone no-code interface described
- Advanced data attributes are billed separately from the free validation
Twilio Lookup FAQ
What does Twilio Lookup do?
It validates phone number format and returns attributes such as provider, line type and line status, along with fraud signals like SIM swap risk.
Is Twilio Lookup free?
Twilio describes basic number validation as free to use, and offers a free trial with no credit card required. Other data attributes are priced separately.
What fraud does it help prevent?
Twilio lists fake account creation, bot attacks, SIM swap, promo abuse and SMS pumping fraud.
How is it accessed?
Through a single REST API, with documentation and code samples on Twilio's developer site.
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Twilio Lookup
Freemium