Caller ID API that blocks spam calls and turns them into revenue

Caller ID API for MVNOs, CPaaS, UCaaS and Voice AI. Block fraud and sell protection as a value-added service.

GET /api/lookup/+18885550147 200 OK
{
  "phone": "+18885550147",
  "reputation": "SPAM",
  "is_spam": true,
  "spam_score": 94,
  "total_complaints": 87,
  "complaints": [
    {
      "Subject": "Reducing your debt",
      "ViolationDate": "2026-07-04"
    }
  ]
}

Trusted by teams at

Two ways it pays for itself

Cut what spam costs your platform, or sell protection to your customers. Most partners end up doing both.

Sell protection as a feature

MVNOs, CPaaS and UCaaS platforms resell spam protection and caller intelligence as a value-added service: a new revenue line that also keeps subscribers around longer.

Stop paying to answer spam

Voice AI platforms run call screening before agents pick up. Fraud never reaches the model, so LLM tokens and telephony minutes stop burning on callers who were never customers.

Building a call blocking app?

Mobile security vendors and MVNOs ship the call blocking SDK under their own brand as a paid tier. New ARPU, lower churn, and anonymous lookups on iOS and Android.

Six products. One data set.

A spam number feed you host, a live spam score, caller names, LRN dips, a voice firewall for live calls and a white-label SDK. Every one of them is built to be resold.

Spam phone number database feed

Every reported number from 195 countries, the last 15 days, hosted on your side. One flat fee, no per-lookup bill, zero latency. Block at the switch, filter outbound traffic, and sell protection on top. See the spam phone number database.

60s

update cadence

Flat fee

for every use case

GET /api/spam-reports/csv 200 OK
$ head -4 spam_numbers.csv
+18882211161
+12099009302
+447476937994
+4930120849110

Live spam score API

One GET returns a spam score from 0 to 100, the reputation and the complaint evidence, refreshed every minute. Drop, label or route the call while it sets up. See the spam call blocking API.

Caller name with the verdict

The business name, industry and city from listings in 195 countries, with the spam verdict in the same response. See the CNAM lookup API.

LRN and carrier dip

The LRN, OCN, SPID, line type and port date of a US number, so calls route to the switch that serves it today. See the LRN lookup API.

Scam detection on live calls

Listens to the caller and returns a scam score, the category and the tactics while the call is on. A scammer on a fresh number still has to say the script. See the voice firewall.

Call blocking SDK

Spam protection inside your own app in about 10 lines of code. MVNOs and security vendors sell it as a paid tier and lift ARPU. Lookups are anonymous on iOS and Android, so a subscriber call log can never leak on our side. See the call blocking SDK.

CallerAPI iOS SDK Swift CallerAPI Android SDK Java / Kotlin CallerAPI Flutter SDK Flutter CallerAPI React Native SDK React Native CallerAPI Asterisk SDK Asterisk

Results we can show. Names we can't.

Spam protection is part of our customers' competitive edge, so deployments sit behind NDAs. Here is recent work, anonymized.

Tens of thousands of dollars in new value-added service revenue

MVNOs, UCaaS providers and platforms with marketplaces resell our spam protection and caller intelligence under their own brand, and keep the margin on every subscriber who upgrades.

A fraud campaign, stopped

A Voice AI CPaaS platform came under a coordinated fraud call campaign. Screening dropped it before it reached their agents or burned their minutes.

Robocalls blocked, under their brand

Niche MVNOs ship robocall blocking to subscribers under their own name, powered by the minute-fresh feed. We stay invisible.

195

countries of business caller data

30

countries of live fraud detection

60s

between blacklist updates

Meets your stack where it is

Turnkey integrations for GoHighLevel, Aircall and Dialpad, licensed directly with pricing scoped to your deployment.

Talk to sales
GoHighLevel
Aircall CallerAPI integration Aircall
Dialpad
Asterisk CallerAPI integration Asterisk

Start at $25. Scale to billions of calls.

Self-serve Caller ID API plans with instant access. Volume, feed and SDK deals are negotiated directly.

See all Caller ID API pricing tiers

Basic

$25/mo

  • 5,000 lookups per month
  • Spam detection and business caller ID
  • No-code integrations
Start now

Premium

Most popular

$99/mo

  • 20,000 lookups per month
  • Everything in Basic
  • Priority support
Start now

Enterprise

$997 pay-per-use

  • 250,000+ lookups
  • Everything in Premium
  • Scalable pricing
Start now

Passing 300,000 lookups a month?

Volume plans run from $1,000 per month up to 50M+ monthly lookups, priced per tier. Tell us your traffic and we quote the exact step.

Talk to sales

Spam phone number database feed

The minute-fresh list for 195 countries, hosted on your side. One flat fee, no per-lookup charges, every use case included.

See the feed

Call blocking SDK licensing

Flat fee, or per subscriber per month with active call blocking. Sell protection as a paid tier under your brand and keep the margin.

See the SDK
Dmitry B, founder of CallerAPI

A note from the founder

I run CallerAPI hands-on. Every case above is real work I was personally in the room for, and every name is protected because our data is part of how those companies win. You get the same discretion.

If you sit anywhere in the call path, tell me what you are dealing with. You will talk to me directly, not a sales team.

Dmitry B.

Founder & CEO, CallerAPI

Speak to the founder

Common questions

Start blocking spam calls today

Grab an API key and make your first lookup in minutes, or run a free caller ID test on any number first.