What is a phone reputation check?

A phone reputation check assesses how much a phone number can be trusted as a contact point for a real person: whether the number is valid and assigned, which carrier holds it, whether it is a mobile line or a VoIP number, and whether anything is registered to it. The purpose is separating a long-held personal mobile from a disposable number acquired for a single account.

Does the Digital Footprint API return a phone reputation score?

No. The API returns phoneDetails with four fields - valid, carrier, lineType and countryCode - plus which platforms the number is registered on. There is no reputation score, no risk score and no fraud rating, because collapsing those facts into a number would hide the reasoning behind a value nobody can audit. Deriving a score from the facts is one line in your own code, and it then carries your thresholds rather than ours.

What is the strongest signal in a phone check?

Line type. A VoIP or non-fixed-VoIP number is cheap, disposable and available in bulk, while a postpaid mobile line requires identity and payment at the carrier. That single distinction separates most disposable numbers from most real ones and costs nothing to read - a VoIP line is not evidence of fraud, but it is a reason to want a second signal.

How many platforms can be checked with a phone number?

5 of them, and phone lookups are in beta. Almost every platform is keyed on an email address or a username, and the handful that accept a phone number are the messaging apps. That is a property of the platforms rather than a limitation of this API, and it is why an email address reaches far further than a number does.

Can a phone number be checked against carrier or spam databases?

Carrier and line type come back from number intelligence, so the carrier question is answered. Spam and scam-report databases are a different source that this API does not query, so no complaint history or spam rating is returned. If a spam list is part of your requirement, treat it as a separate vendor and combine the two rather than expecting one answer here.

Phone reputation check: what a number can and cannot tell you

Updated 2026-08-31

A phone reputation check is meant to answer whether a number belongs to a real, reachable person or to a disposable VoIP line bought for one signup. This guide covers the signals that genuinely answer that - line type, carrier, validity and messaging-app registration - explains why this API deliberately returns no reputation score, and is explicit that phone coverage here is in beta and narrower than email.

What actually comes back

A phone lookup returns two things: number intelligence, and registration on the platforms that accept a phone number as input. Both are facts with a source, and neither is a rating.

200 OK

{
  "query": "+14155550123",
  "queryType": "phone",
  "matches": 2,
  "results": [
    { "platform": "whatsapp", "registered": true,  "method": "public_api", "checkedAt": "2026-08-31T09:12:04.1Z" },
    { "platform": "telegram", "registered": true,  "method": "public_api", "checkedAt": "2026-08-31T09:12:04.3Z" }
  ],
  "phoneDetails": {
    "valid": true,
    "carrier": "Verizon Wireless",
    "lineType": "mobile",
    "countryCode": "US"
  },
  "breaches": null,
  "webMentions": null
}

// Note: no "riskScore", no "reputation". Those fields do not exist here.

Read phoneDetails.lineType first. It carries more weight than the other three fields combined, for the reason below.

Line type is the signal that matters

Numbers are not interchangeable. A postpaid mobile line is issued by a carrier that took identity and payment details for it, and it is expensive and slow to acquire in volume. A non-fixed-VoIP number can be provisioned in seconds, in bulk, from a browser, and discarded just as fast. When a fraud team asks whether a number is “good”, this is very nearly the whole question.

What line type does not tell you is whether the person is legitimate. Plenty of real people use VoIP numbers deliberately - remote workers, people who moved country, anyone who prefers not to hand out a personal mobile. It is a reason to want a second signal, not a reason to decline.

Registration: narrow, and honest about it

Only 5 platforms in the registry accept a phone number, and they are essentially the messaging apps. There is no version of this API where a phone number reaches the coverage an email address does, because the platforms themselves do not offer it - most have no way to ask “does an account exist for this number” at all.

So a phone registration result is a bonus signal rather than a foundation. A number registered on a messaging app is weak positive evidence that it belongs to a person; a number registered on none of them establishes very little, given how few were checked. When you hold both a number and an email address, run the address - see the email enrichment API. Phone lookups remain in beta, and the phone lookup guide sets out what that means.

Why there is no reputation score

Every input to a score is already in the response: validity, carrier, line type, country and registration. Turning them into a single number would add no information - it would only move the thresholds from your code into ours, where you cannot see them, cannot tune them for your population, and cannot explain them to a reviewer who asks why an application was declined.

Score it yourself, on the facts, and keep the facts beside the score. That is the same rule applied throughout: breaches and webMentions come back null when a source is not configured rather than empty, and a platform that could not be confirmed is omitted rather than reported as false. A number you cannot audit is worse than no number.

Frequently asked questions

What is a phone reputation check?: A phone reputation check assesses how much a phone number can be trusted as a contact point for a real person: whether the number is valid and assigned, which carrier holds it, whether it is a mobile line or a VoIP number, and whether anything is registered to it. The purpose is separating a long-held personal mobile from a disposable number acquired for a single account.
Does the Digital Footprint API return a phone reputation score?: No. The API returns phoneDetails with four fields - valid, carrier, lineType and countryCode - plus which platforms the number is registered on. There is no reputation score, no risk score and no fraud rating, because collapsing those facts into a number would hide the reasoning behind a value nobody can audit. Deriving a score from the facts is one line in your own code, and it then carries your thresholds rather than ours.
What is the strongest signal in a phone check?: Line type. A VoIP or non-fixed-VoIP number is cheap, disposable and available in bulk, while a postpaid mobile line requires identity and payment at the carrier. That single distinction separates most disposable numbers from most real ones and costs nothing to read - a VoIP line is not evidence of fraud, but it is a reason to want a second signal.
How many platforms can be checked with a phone number?: 5 of them, and phone lookups are in beta. Almost every platform is keyed on an email address or a username, and the handful that accept a phone number are the messaging apps. That is a property of the platforms rather than a limitation of this API, and it is why an email address reaches far further than a number does.
Can a phone number be checked against carrier or spam databases?: Carrier and line type come back from number intelligence, so the carrier question is answered. Spam and scam-report databases are a different source that this API does not query, so no complaint history or spam rating is returned. If a spam list is part of your requirement, treat it as a separate vendor and combine the two rather than expecting one answer here.

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