Validate Phone Numbers in Real Time
Carrier lookup, line type detection, format normalization, and country code parsing — all from a single API call.
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What the Phone Validation API Does
One endpoint. Everything you need to know about a phone number — validity, carrier, line type, and normalized format.
Accuracy
Every response includes country and region detection, carrier name, line type classification (mobile, landline, VoIP), and the phone number formatted to E.164 international standard — all normalized into a consistent JSON structure.
{
"valid": true,
"country": "US",
"country_code": 1,
"carrier": "Verizon",
"line_type": "mobile",
"e164": "+14155552671",
"local": "(415) 555-2671"
}
Simplicity
A single GET request with your API key is all it takes. No SDK, no configuration, no setup — just an HTTP call and a JSON response.
GET /v1/validation/phone?number=%2B14155552671
Host: requiems.xyz
requiems-api-key: YOUR_API_KEY
Validate Phone Numbers in Any Workflow
From fraud prevention to onboarding — if it touches a phone number, this API has you covered.
Auth / Signup
Verify phone numbers at registration
Ensure every phone number is real, reachable, and correctly formatted before accepting it during user signup.
Fraud Prevention
Detect VoIP and virtual numbers
Flag disposable or virtual phone numbers used by bad actors. Block high-risk line types during sensitive operations.
Integrations
Validate phone data in workflows
Normalize and validate partner-provided phone numbers before they enter your CRM, billing, or support systems.
SMS Marketing
Confirm mobile numbers for campaigns
Filter for mobile-only line types before sending SMS. Reduce undelivered messages and protect sender reputation.
Onboarding
Standardize international numbers
Convert phone numbers from any country into E.164 format automatically. One consistent format across your entire user base.
Support
Look up caller info in real time
Identify carrier and country from an incoming phone number during support calls. Route to the right team instantly.
Pair It With Other APIs
Combine Phone Validator with other Requiems APIs to build multi-point validation into a single workflow.
Phone Validator + Email Validator
Benefit: Validate phone and email in the same onboarding step.
Outcome: Complete contact verification — reachable phone and deliverable email — before granting access.
Phone Validator + Email Normalizer
Benefit: Normalize email and validate phone together.
Outcome: Consistent, verified contact data across both channels from a single API call.
Phone Validator + Domain Checker
Benefit: Verify phone number and check domain reputation at once.
Outcome: Multi-point identity confidence — confirmed phone, healthy domain — for high-risk signups.
Frequently Asked Questions
Still have questions?
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One API key. Phone validation, email verification, domain checks, and 50+ other APIs across validation, networking, finance, and more.