Contact Services
Phone Validation & Carrier Lookup API
Validate, format, and enrich phone numbers — carrier name, line type, country, and national/international formats. Australian and international support.
A phone number can look valid and still be useless. Is it a mobile or a landline? Is the carrier active? Is it a VoIP number being used for fraud? If you're collecting phone numbers without validating them, you're flying blind.
The Checkify phone validation endpoint parses, validates, and enriches phone numbers. It returns the carrier name (Telstra, Optus, Vodafone, etc.), line type (mobile, fixed-line, VoIP, toll-free, premium-rate), country, and formatted versions in both national (0412 345 678) and international (+61 412 345 678) formats.
The default country is Australia, but the endpoint supports international numbers too — pass a country code parameter to validate numbers from any country. For batch processing, upload a CSV through the bulk endpoint.
The line type classification is the bit most people overlook. If you're running an SMS campaign, you need mobile numbers — sending to a landline or VoIP number just wastes credits and inflates your failure stats. If you're doing 2FA, a VoIP number is a red flag worth investigating. A toll-free number on a customer registration form probably means something's wrong. Knowing the line type before you act on the number saves money and catches suspicious activity early.
Phone formatting is the other practical win. Australian numbers show up in databases in every imaginable format — 0412345678, +61412345678, (04) 1234 5678, 04-1234-5678 — and they all mean the same thing. The endpoint normalises everything to consistent national and international formats, so your database isn't full of duplicates that only differ by spacing and punctuation. For the other half of contact validation, the email validation endpoint checks syntax, DNS, SMTP deliverability, and flags disposable providers.
What you get
Endpoint capabilities and technical details.
Carrier detection
Identifies the mobile or fixed-line carrier — Telstra, Optus, Vodafone, TPG, and others. Useful for SMS routing and cost estimation.
Line type classification
Classifies numbers as mobile, fixed-line, VoIP, toll-free, premium-rate, shared-cost, pager, or personal number. Critical for SMS campaigns (only mobile numbers receive SMS).
National and international format
Returns the number in both national (0412 345 678) and international (+61 412 345 678) formats. Handles any input format — spaces, dashes, parentheses, or raw digits.
Country support
Defaults to Australia (AU) but accepts any ISO country code. Validate and format numbers from any country.
Geographic location
For Australian numbers, returns the state or region associated with the number prefix. Useful for regional segmentation.
Bulk processing
Upload a CSV of phone numbers for batch validation. Clean your entire contact database in one job.
Why use this endpoint
SMS-ready contact lists
Filter your contact list to mobile numbers only before running an SMS campaign. Avoid wasting credits on landlines, VoIP, and invalid numbers.
Fraud detection
Flag VoIP and virtual numbers during account signups. Combine with carrier data and line type to build risk profiles.
Consistent formatting
Store every phone number in a consistent format. No more "0412345678" vs "+61 412 345 678" vs "(04) 1234-5678" scattered through your database.
Built for your industry
Common use cases across industries that rely on validated Australian data.
Marketing & SMS
Validate and classify phone numbers before SMS campaigns. Only send to mobile numbers. Estimate costs by carrier.
Fintech & Banking
Phone validation during account opening. Flag VoIP numbers as higher risk for 2FA and identity verification.
Telecommunications
Number portability checks, carrier identification, and line type classification for porting and provisioning workflows.
Healthcare
Validate patient phone numbers to ensure appointment reminders and test results reach the right person via the right channel.
Recruitment
Verify candidate phone numbers before scheduling interview calls. Ensure you're calling a working number.
Trusted data, transparent pricing
Phone validation combines local number parsing (libphonenumber) with an external carrier lookup service. No calls or messages are made to the validated number. The service identifies the carrier and line type based on number prefix databases.
Source: libphonenumber + carrier database
How search units work
Checkify uses a simple unit-based model. Each paid API call costs 1–3 search units depending on the endpoint. Your monthly plan includes a set number of units — use them on any endpoint, any time. No hidden fees.
This endpoint: 1 unit per call
1 unit deducted per successful API call.
Ready to integrate?
One REST endpoint, JSON responses, Bearer token auth. No SDK required — just HTTP. Check the full docs for parameters, response schemas, and error codes.
curl -H "Authorization: Bearer ck_prv_..." \ "https://checkify.com.au/api/v1/phone?phone=0412345678"
{
"phone": "+61412345678",
"phoneNational": "0412 345 678",
"phoneInternational": "+61 412 345 678",
"valid": true,
"country": "AU",
"type": "mobile",
"carrier": "Telstra",
"location": "New South Wales"
}
Frequently asked questions
Does this call the phone number?
Can it detect ported numbers?
Does it work for international numbers?
What line types are detected?
Can I validate phones in bulk?
More Contact Services
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