Phone validation API · Real-time checks · $0.001 / lookup

Phone Validation API — Real-time Verification, $0.001/Lookup

Add real-time phone validation to signup forms, lead capture, fraud review, CRM imports, and campaign workflows with bulkchecker.io.

Latency

Sub-100ms response

Reliability

99.99% uptime

Coverage

240+ countries

Get Started Sign up

POST /v1/validate

curl -X POST https://api.bulkchecker.io/v1/validate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"phone":"+14155550198"}'

Response preview

validtrue

line_typemobile

carrierdetected

risk_score8

Capabilities

API Capabilities

Use one API to validate phone quality, enrich records, and route risky numbers before they enter production workflows.

Validity check (real & active)

Determine whether a phone number appears valid, assigned, and currently in service.

Carrier & line type

Identify carrier and classify mobile, landline, VoIP, toll-free, and other line types.

Risk scoring

Score risky, unusual, or disposable phone signals before signup, KYC, or campaign actions.

Country/region detection

Resolve country, region, and normalized international phone format for storage and routing.

3-minute integration

Quick Start

Create a key, make your first lookup, and use the JSON response to block, allow, or review a number.

Get your API key

Create a project in bulkchecker.io, generate a server-side API key, and set usage limits for your team.

Make your first call

curl -X POST https://api.bulkchecker.io/v1/validate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "phone": "+14155550198"
  }'

Sample response

{
  "phone": "+14155550198",
  "valid": true,
  "active": true,
  "line_type": "mobile",
  "carrier": "detected",
  "country": "US",
  "region": "California",
  "risk_score": 8,
  "normalized": "+14155550198"
}

Reference

Endpoints Overview

Use single-number validation, bulk jobs, or carrier-only enrichment depending on the workflow.

GET

GET /v1/validate

Validate one phone number for real-time form checks, registration flows, and lead capture.

POST

POST /v1/validate/bulk

Submit large batches for background processing, export, and CRM list cleaning.

GET

GET /v1/carrier

Return carrier, line type, and country data when you need enrichment without full scoring.

Integration stack

SDKs & Integrations

Ship validation in your existing backend stack with simple request patterns and predictable JSON responses.

Python

Node

Ruby

PHP

.NET

Volume tiers

Pricing

Start at $0.001 per lookup, then move into higher-volume tiers as validation traffic grows.

Monthly volume	Price / lookup	Best for	Included
0 - 100K	$0.0010	Testing and early production	Single lookup, bulk endpoint, API dashboard
100K - 1M	$0.0008	Growth teams and CRM automation	Priority queue, usage alerts, CSV exports
1M - 10M	$0.0006	High-volume validation	Bulk jobs, team access, higher rate limits
10M+	Custom	Enterprise data operations	Custom SLA, dedicated support, volume contract

Developer workflows

Use Cases for Developers

Add validation wherever phone quality affects conversion, deliverability, fraud risk, or data hygiene.

Real-time form validation

Catch fake or invalid phone numbers before a user submits a lead form or checkout flow.

User registration verification

Score a number at signup and route high-risk profiles into review before activation.

Bulk list cleaning workflow

Validate imported CRM lists and marketing audiences before sending SMS or WhatsApp campaigns.

Comparison

Compare with Twilio Lookup / Numverify API

Compare validation scope, bulk support, pricing, and developer workflow fit before choosing an API.

Feature	bulkchecker.io	Twilio Lookup	Numverify API
Real-time validation	Yes	Yes	Basic lookup
Bulk endpoint	Built in	Custom workflow	Limited
Risk scoring	Included	Depends on setup	Not primary
Entry price	$0.001 / lookup	Usage-based	Plan-based

FAQ

Short answers for developers evaluating the bulkchecker.io Phone Validation API.

What's your API rate limit?

Rate limits depend on plan and volume tier. Higher-volume plans include higher throughput and optional dedicated limits.

Do you support webhook notifications?

Yes. Webhook notifications can be used for bulk validation jobs, completed exports, and async workflow updates.

Is there an SLA?

Enterprise plans can include an SLA, dedicated support, and custom operational requirements.

What about data privacy?

The API is designed for server-side validation, controlled access, and privacy-aware handling of phone data.

Do you have free credits to test?

Yes. Developers can request test credits to validate integration behavior before moving to production volume.

Is this a phone validator API and bulk phone validation API?

Yes. The same endpoint serves as a phone validator API for real-time checks and a bulk phone validation API for high-volume jobs. Send single numbers via REST or upload arrays of up to 10,000 per call.

Do you offer a phone number verification API with line type and risk score?

Yes. The phone number verification API returns line type (mobile, landline, VoIP), carrier name, country code, and a risk score per number. Suitable for signup forms, KYC flows, and CRM enrichment.

Start Real-time Phone Validation

Get an API key, make your first request, and validate phone quality before bad data reaches production.

Get API Key See pricing