What is a Risk Score?
A risk score is a number from 0 to 100 that tells you how much you should trust a phone number.
Lower is better. 0 means we found no warning signs. Higher means more warning signs, so you should look closer.
How to read the score
Think of it like a traffic light. The website also shows the same number as a Trust score (100 minus the risk score), so 0 risk = 100% trust.
Looks like a normal, real phone number. Safe to contact or accept.
Something looks a little unusual. Worth a second check, such as an OTP or a quick review.
Several warning signs. Verify before you trust it, or block it if your use case is strict.
What we look at
We check each number for warning signs. Every sign adds to the score. The more signs, the higher it goes (it stops at 100).
What kind of line it is
Regular mobile and landline numbers are the norm. Internet-based (VoIP) lines, premium-rate numbers and toll-free numbers are easier to get anonymously, so they raise the score.
Who runs the line
Numbers issued by big consumer carriers look normal. Numbers from cloud-calling and app-based providers, or numbers where no carrier can be found at all, raise the score a little.
How the digits look
Real numbers rarely look like 1111111111, 1234567890 or 123123123. Very short numbers and obvious patterns are typical of made-up entries.
Throwaway numbers
Temporary and disposable numbers are made to be used once and dropped. They are a common sign of fake sign-ups.
Known trouble spots
Some area codes are linked to premium-rate call-back scams, and some regions see more fraud than others. Numbers from these places get extra attention.
Is it a real, assigned number?
We check whether the number range has actually been handed out. Made-up numbers, like the fictional 555-01xx range used in movies, score very high.
Three examples
Illustrative numbers, to show how the score behaves in real life.
- Mobile line
- Major carrier
- Normal-looking digits
Nothing unusual. Treat it like any real customer.
- VoIP line
- Cloud-calling carrier
Not necessarily bad, since many real businesses use VoIP. But worth a quick check.
- In the fictional 555-01xx range
- Never assigned to a real person
This is a made-up number. Block it, or ask for a real one.
What should I do with it?
The score is a guide. You decide where to draw the line for your business.
Ask for an OTP when the score is 25 or higher; block above 75 if you want strict sign-ups.
Sort your list by risk score. Call low-risk leads first and review the rest.
Remove high-risk numbers before you send. You save money and protect your sender reputation.
Use it as one signal next to email, IP and device, never as the only one.
The warning signs, explained
Every result lists the warning signs it found (riskFlags), so you always know why a number scored the way it did.
voipThe number is an internet-based line, not a traditional mobile or landline.voip_carrierThe carrier is a cloud-calling or app-based provider.disposable_numberThe number belongs to a temporary, throwaway service.premium_rateCalls to this number cost extra, which is often abused in scams.toll_freeA free-to-call business line. Common for companies, rare for individuals.repeated_digitsThe same digit repeats over and over, e.g. 88888888.sequential_digitsThe digits run in order, e.g. 1234567890.pattern_digitsA short group of digits repeats, e.g. 123123123.short_numberThe number is shorter than a real phone number should be.high_risk_countryThe number is from a region with higher-than-average phone fraud.caribbean_premium_trapThe area code is linked to "one-ring" call-back scams.fictional_numberThe number sits in a range reserved for TV and film.unknown_carrierWe could not find which carrier the number belongs to.unassigned_prefixThe number range has not been given out to any carrier.fake_numberConfirmed by our data provider as not a real line. Always scores 100.Using it in your product
The score comes back on every validation, with no extra call needed. Check it in your code and decide what to do.
Read the API docs{
"isValid": true,
"lineType": "voip",
"carrier": "Twilio",
"riskScore": 45,
"riskFlags": ["voip", "voip_carrier"]
}Common questions
Does a high score mean this person is a fraudster?
No. It means the number has more warning signs. A real person can have a VoIP number or an unusual-looking one. Treat the score as a reason to look closer, not as a verdict.
Does a score of 0 mean the number is guaranteed safe?
No score can promise that. A score of 0 means we found none of the usual warning signs, which is a very good sign, but not a guarantee.
What is the difference between the risk score and the trust score?
They are the same measurement from opposite sides. Trust = 100 minus Risk. Our website shows Trust because "100% trusted" is easier to read. The API returns riskScore.
Is the score different from "valid"?
Yes. "Valid" tells you the number is properly formed and exists. The risk score tells you how much you should trust a valid number. A number can be valid and still have a high risk score.
Where do I find it?
On every validation result: in the website checker, in your dashboard, in bulk-validation files, and in the API as riskScore and riskFlags.
Can I see why a number got its score?
Yes. Every result includes riskFlags, a list of the warning signs we found, so you can see exactly what pushed the score up.