Fraud detection & risk signals

Every fraud
has a tell.

Q: Can I use a single signal on its own?

Yes. /v1/phone, /v1/email and /v1/ip each sell one signal at its own rate, and file uploads run them over a whole list. /v1/assess is the one endpoint that scores.

ProofTell checks a phone number, an email address and an IP address in one API call, and returns a risk score, a verdict and the reasons behind it.

Sandbox keys are free. Evaluating for your company? Ask for a $10 credit from your dashboard.

Sign-up check

+1 500 555 0002

3 signals · reference signup-48213

Deny95 / 100

The IP address is a Tor exit node.
203.0.113.66
+40
The email address uses a disposable provider.
disposable@sandbox.prooftell.com
+35
The number is a VoIP line, easy to obtain anonymously.
+1 500 555 0002
+20

Checkout check Allow

order-77300 / 100

Valid mobile lineMailbox existsSame country

Phone engine: Veriphone; In production since 2019
Email engine: Verimail; Asks the mail server, sends nothing
Phone coverage: 243; Countries and territories
Hosting: European Union; Belgium, on Google Cloud

One call

Send what you know. Get back what matters.

1
Send a phone, an email, an IP, or all three
Whatever you collect at sign-up, login or checkout.
2
We run every signal in parallel
The numbering plan and line type, the mailbox and its domain, the network behind the address.
3
You get a score, a verdict and the tells
A number from 0 to 100, allow, review or deny, and every point explained in plain words.

The sample is the sandbox’s real answer. Run it with a pt_test_ key and you get exactly this, free. With a live key the same call costs $0.0045.

Read the API reference

cURLNode.jsPython

curl https://api.prooftell.com/v1/assess \
  -H "Authorization: Bearer $PROOFTELL_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "phone": "+15005550002",
    "email": "disposable@sandbox.prooftell.com",
    "ip": "203.0.113.66",
    "reference": "signup-48213"
  }'

const res = await fetch("https://api.prooftell.com/v1/assess", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.PROOFTELL_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    phone: "+15005550002",
    email: "disposable@sandbox.prooftell.com",
    ip: "203.0.113.66",
    reference: "signup-48213",
  }),
})
const { score, verdict, reasons } = await res.json()

import os, requests

res = requests.post(
    "https://api.prooftell.com/v1/assess",
    headers={"Authorization": f"Bearer {os.environ['PROOFTELL_KEY']}"},
    json={
        "phone": "+15005550002",
        "email": "disposable@sandbox.prooftell.com",
        "ip": "203.0.113.66",
        "reference": "signup-48213",
    },
)
result = res.json()
print(result["verdict"], result["score"])

Response

{
  "id": "asm_oxyq6rmz74bzsrxm",
  "mode": "test",
  "reference": "signup-48213",
  "score": 95,
  "verdict": "deny",
  "reasons": [
    { "code": "phone_voip", "points": 20,
      "message": "The number is a VoIP line, easy to obtain anonymously." },
    { "code": "email_disposable", "points": 35,
      "message": "The email address uses a disposable provider." },
    { "code": "ip_tor", "points": 40,
      "message": "The IP address is a Tor exit node." }
  ],
  "signals": {
    "phone": { "status": "ok", "cost": "0.0000", "result": { … } },
    "email": { "status": "ok", "cost": "0.0000", "result": { … } },
    "ip":    { "status": "ok", "cost": "0.0000", "result": { … } }
  },
  "ruleset": "2026-10-01",
  "cost": "0.0000",
  "currency": "USD",
  "createdAt": "2026-10-01T07:55:41Z"
}

The tells

Fraud leaves traces. We know where to look.

No black box. Every score comes with the signals that drove it, so your team can explain every decision, to a customer or to an auditor.

Phone

VoIP or virtual number

Cheap to create by the thousand and easy to obtain anonymously. The favorite of fake-account farms.

Phone

A number that cannot exist

Wrong length, unassigned prefix, a typo or an invention. It fails the numbering plan of its own country.

Disposable inbox

A mailbox that expires in ten minutes rarely belongs to a customer who plans to stay.

A mailbox nobody owns

The mail server says there is no such user. Real customers give addresses that receive mail.

Hidden network

Tor exits, VPN providers and datacenter ranges, where real shoppers rarely come from.

Phone + IP

Two countries at once

A number from one country, a connection from another. Not damning alone; it weighs in with the rest.

One platform

Every signal you need. One API key, one balance.

Score an identity in one call, or buy each signal on its own. By API, or over a whole file.

Risk score

One call, three signals: a 0 to 100 score, a verdict and the reasons.

POST /v1/assess

Phone intelligence

Validity, line type, carrier and country for any number.

POST /v1/phone

Email verification

Whether the mailbox exists, without sending a message.

POST /v1/email

IP intelligence

Tor, VPN and datacenter detection, location and network.

POST /v1/ip

Bulk verification

Upload a CSV or Excel file, download it back with every row checked.

POST /v1/files

Pay in dollars

One balance for every check. No credits to decode, no plans, nothing that expires.

GET /v1/balance

Explainable by design

A score your team can defend.

Every point has a reason: Each rule that fires adds points and a sentence. The score is their sum, capped at 100. Nothing hides inside a model.
The cut-offs are yours: You decide where review starts and where deny starts, per organization, from the dashboard.
A versioned rule set: Every response names the rule set that produced it, so a decision can still be explained after the rules have moved on.
An outage never lowers the bar: When a signal cannot answer, the response says so and the verdict is raised to at least review. A gap is never filled with a guess.

How the score works

+44 7700 900123

3 signals · rule set 2026-10-01

Review

45 / 10020 + 15 + 10

0Allow · Review · Deny100

The IP address belongs to a VPN provider.
+20
The phone number’s country (GB) differs from the IP address’s (NL).
+15
The domain accepts any address, so the mailbox could not be confirmed.
+10

phone	email	pt_phone_type	pt_email_result
+14155550132	dana@northwind.example	mobile	deliverable
+442079460958	sales@contoso.example	fixed_line	catch_all
+15005550002	x9@tempbox.example	voip	disposable
+33639980123	lee@fabrikam.example	mobile	undeliverable

Bulk

A whole file, checked the same way.

Upload a CSV or an Excel file, pick the columns, and download it back with the results added to every row, in the order you sent them. Duplicates run once. Files are deleted 30 days after upload.

Bulk verification

Pricing

Pay for what you check. In dollars.

One public rate card for everyone. You are charged per signal that returns a result, from a balance that never expires.

Phone intelligence

$1.00 per 1,000

$0.0010 per number.

Email verification

$3.00 per 1,000

$0.0030 per address.

IP intelligence

$0.50 per 1,000

$0.0005 per address.

Full risk check

$4.50 per 1,000

Phone, email and IP in one call, scored. $0.0045 per check.

Volume is rewarded on the money, not on the rate: top up $5,000 and we add $750. Enterprise contracts are invoiced.

See the rate card

Security & privacy

Built to keep little. Written to pass a review.

Where your data goes, who touches it and when it is deleted are published, down to the sub-processor list and the things we do not have.

Hosted in the EU

The API, the database and file storage run in Belgium, on Google Cloud.

Retention you control

Assessments are kept 90 days by default. Choose a shorter period, or zero, and nothing is stored.

Inputs stay out of logs

Phone numbers, addresses and IPs travel in request bodies and never reach our logs or error messages.

A DPA you can file today

Pre-signed, GDPR Article 28, applies to every account. No call, no countersignature.

Security & sub-processors Data processing agreement GDPR Enterprise agreement

Where it pays off

One check, at every door.

Account opening

Score every sign-up before it costs you a welcome bonus, a free trial or a support ticket.

Checkout

Send the order’s phone, email and IP. Let the clean ones through, hold the rest for a second look.

Lead capture

A real mobile line and a mailbox that exists are stronger buying signals than a form that was merely filled in.

List hygiene

Upload the file you already have and get it back with every phone, address and IP checked.

FAQ

Questions, answered plainly.

What does ProofTell check?

Three things about the person in front of you: the phone number (is it valid, what kind of line, which carrier, which country), the email address (does the mailbox exist, is it disposable, a catch-all or a role account) and the IP address (Tor, VPN or datacenter, and where it is). The risk score weighs them together.

How is the score calculated?

By a transparent, versioned set of rules. Each rule that matches adds points and a readable reason; the score is the sum, capped at 100; your thresholds turn it into allow, review or deny. There is no machine-learning model in the path, so the same signal results always give the same score, and every score can be explained.

What happens when one of the signals is down?

You still get an answer. The score comes from the signals that ran, the missing one is reported as unavailable at no charge, and the verdict is raised to at least review, so an outage can never turn a deny into an allow. If none of the signals you asked for could run, the call fails with a 503 and your own fallback applies.

Do you contact the person I am checking?

No. Nothing is sent to the phone and no message lands in the inbox. The email check asks the mail server whether the mailbox exists and stops before any message is delivered. ProofTell does not send one-time codes.

Can I use a single signal on its own?

Yes. /v1/phone, /v1/email and /v1/ip each sell one signal at its own rate, and file uploads run them over a whole list. /v1/assess is the one endpoint that scores.

How much does it cost?

You pay per signal that returns a result, from one balance in US dollars: $1.00 per 1,000 for phone intelligence, $3.00 per 1,000 for email verification, $0.50 per 1,000 for IP intelligence. A full check with all three is $4.50 per 1,000. No plans and no credits. The pricing page has the whole rate card.

Is there a free trial?

There is no free plan. Sandbox keys are free: they return simulated, deterministic results for documented inputs, so you can build your integration without paying. If you are evaluating ProofTell for your company, sign up with your work email and ask for a $10 evaluation credit from the Billing page of your dashboard.

Where is my data processed, and for how long is it kept?

In the European Union, in Belgium, with one exception the email check requires: asking an address’s mail server whether the mailbox exists goes through verification servers in several countries. Single lookups are not stored. Assessments are kept for 90 days by default so you can review them, and you can choose a shorter period or switch storage off. Uploaded files are deleted 30 days after upload, or as soon as you delete them. The security page has the detail.

Do you sign a DPA, or our own contract?

The data processing agreement is published and pre-signed, and applies to every account. If your policies require a signed master services agreement, a service level agreement or a negotiated DPA, that is what the enterprise agreement is for.

Find the tell before it costs you.

Create an account, take a sandbox key, make your first call in minutes.

Every fraudhas a tell.

Send what you know. Get back what matters.

Fraud leaves traces. We know where to look.

VoIP or virtual number

A number that cannot exist

Disposable inbox

A mailbox nobody owns

Hidden network

Two countries at once

Every signal you need. One API key, one balance.

Risk score

Phone intelligence

Email verification

IP intelligence

Bulk verification

Pay in dollars

A score your team can defend.

A whole file, checked the same way.

Pay for what you check. In dollars.

Built to keep little. Written to pass a review.

Hosted in the EU

Retention you control

Inputs stay out of logs

A DPA you can file today

One check, at every door.

Account opening

Checkout

Lead capture

List hygiene

Questions, answered plainly.

Find the tell before it costs you.

Every fraud
has a tell.