How to Identify and Block Fake Phone Numbers in SaaS Applications
Complete guide for SaaS platforms to identify and block fake phone numbers, disposable numbers, and VoIP fraud. Learn implementation steps, best practices, and key metrics to monitor.
Protect your application from fake and disposable phone numbers.
Fraudsters and bots use virtual and burner phone numbers to sign up to your service.
Our fake number checker identifies disposable, temporary, VoIP and virtual numbers in real time so you can protect your service from spam and fraud.
Fake Number Checker
Looking up phone number...
They verify phone numbers with NumCheckr
Prevent bots and fake accounts creation
Detect virtual and disposable numbers
A lot of shady websites provide temporary phone numbers for the sole purpose of receiving OTPs and bypassing phone number verifications. Fraudsters and bots use this to create fake accounts and spam your service. Our fake number checker and phone intelligence API help you block free, virtual, disposable and burner numbers before OTP.
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HLR Lookup
- Reduce fraud and clean up your database by implementing phone number validation. Identify the line type, whether it's mobile, landline, VoIP, temporary, and more.
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API-based
- Integrate our API to verify phone numbers before they create an account on your platform. Get detailed reports, risk scoring, and comprehensive phone number information.
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Mobile-based identity intelligence
- We continuously monitor hundreds of Public SMS Gateways (PSGs) and maintain connections with mobile operators globally.
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120+ countries covered
- Phone numbers from all over the world are covered, including the US, Canada, UK, Germany, France, Italy, Spain, and many more.
API Support
Fake number lookup & phone validation API in minutes
Our API makes it simple to implement fake phone number verification in your application. Ideal for registration forms and user verification processes, it helps filter out disposable and virtual numbers before OTP. Use it as a virtual number checker, burner phone detector, or bot phone number check depending on your policy.
- Low-latency.
- Don't slow down your application. Get results you need in less than 80ms.
- Always up.
- We guarantee a 99.995% uptime SLA. Our API is always available when you need it.
Terminal
curl
curl -X POST numcheckr.com/api/check-number \
-d '{ "phone": "+447497265710" }'
{
"active_line": true,
"is_disposable": true,
"public_sms_gateways": [
"online-sms.org",
"sms24.me"
],
"type": "MOBILE",
"country_code": "gb",
"country_name": "United Kingdom",
"carrier": "EE",
"e164_format": "+447497265710",
"national_format": "07497 265710",
"international_format": "+44 7497 265710"
...
}
CSV and Excel support
Sanitize your CSV and Excel files
With our bulk validation module, you can verify thousands of phone numbers at once and flag the ones that don't belong to real users.
- Upload a file.
- Upload your CSV or XLS file containing the phone numbers you wish to verify.
- Download the report.
- Receive a detailed XLS report which instantly identifies phone numbers that do not belong to real users.
- Take action.
- Protect your application from fraudsters and bots you've identified.
FAQ
Quick answers about fake number checking and virtual number detection.
How do I tell if a phone number is fake?
Look for VoIP carrier registration, presence on public SMS gateways, short lifespans and reuse across accounts. Our fake number checker and detector analyze these signals and more in real time.
How do I identify a virtual phone number (VoIP)?
Use a virtual number checker that combines carrier type, allocation (NPA‑NXX), and live blacklist intel from public SMS inboxes and rental providers. NumCheckr does this automatically.
What is a burner phone checker or detector?
A burner phone checker flags temporary, disposable or prepaid ranges frequently used for spam and trial abuse so you can block or step‑up verification before sending OTP.
What is a bot phone number check?
It screens numbers for automation indicators—public inbox reuse, VoIP allocations and velocity patterns—so bots can’t mass‑create accounts with fake numbers.
Last Articles
Read the latest articles from our blog.
Fake Number Checker: Detect Virtual & Burner Phone Numbers
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Disposable Phone Numbers: What "Your Code is 0000" Reveals
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Phone Number Validation: How to Detect Fake Numbers
Learn strategies for validating phone numbers to detect fake ones, and how to apply them in your account creation process. Multiple layers of verification and validation need to be considered to avoid your verification process being bypassed by fake phone numbers.