Telephony and contact center

Check carriers, phone numbers and phone complaints in PhoneBurner

Look up the original carrier, state and rate center of US numbers on a PhoneBurner call list, so lists can be grouped by region before a dialing session.

Why the data matters in PhoneBurner

A power dialer lives on list quality: each number that sits in an unassigned block or belongs to the wrong region costs a dial slot and a rep a few seconds of silence. PhoneBurner contacts can carry custom fields (text, checkbox, date, drop down or numeric) that you can write through its REST API, so the issuing state and rate center of each US number can sit on the contact and call blocks can be built from it.

What LookValid checks

LookValid checks for PhoneBurner
Product	What it does here	Credits
Carrier Lookup (original carrier)	Returns the carrier originally assigned the US number block, plus state and rate center and whether the block is in service. It does not reflect porting, so it is not the current carrier.	1 credit per lookup (numbers outside the covered numbering plan areas are free)
Phone Numbering-Plan Validation	Formats a number to E.164 and checks it against the numbering plan, returning the type the plan assigns. It cannot tell if the line answers.	1 credit per valid number
Phone Spam Check	Reports how many consumer complaints exist for a number in public complaint data. Those are raw consumer reports, not a ruling about the caller.	1 credit per number with complaints on record

Connect it in four steps

Sign up at LookValid and create an API key from the dashboard.
Collect the numbers to check, either by reading contacts through the PhoneBurner REST API (a GET on /rest/1/contacts with your PhoneBurner bearer token) or from a list file you own, and set LOOKVALID_API_KEY in the shell that runs the job, apart from that PhoneBurner token.
Call the carrier lookup for each number; a found value of false means the block has no record, so leave that contact blank and keep it for review, and stop on an error answer.
Create custom fields named Number State, Rate Center and Block In Service in PhoneBurner (a text field type fits the first two), then write each value onto its contact with a PUT to the contact custom field route, which takes the new value in the request body.

A shell job that reads one number at a time, from contacts you pull with the PhoneBurner contacts route or from a list file, and prints the fields to store on each contact. The call is POST https://YOUR_API_HOST/v1/carrier-lookup and costs 1 credit per lookup (numbers outside the covered numbering plan areas are free).

lookup_phoneburner_block.sh

1#!/bin/sh
2# Usage: lookup_phoneburner_block.sh <value>
3set -eu
4jq -n --arg value "$1" '{"phone": $value}' \
5  | curl --fail-with-body -sS -X POST "https://YOUR_API_HOST/v1/carrier-lookup" \
6      -H "Authorization: Bearer $LOOKVALID_API_KEY" \
7      -H "Content-Type: application/json" \
8      -d @- \
9  | jq 'if .error then ((.error.code + ": " + .error.fix + "\n") | halt_error(1)) elif .found then {"Number State": .data.state, "Rate Center": .data.rate_center, "Block In Service": .data.in_service} else null end'

Where each response field goes in PhoneBurner
Response field	Goes into
data.state	Number State
data.rate_center	Rate Center
data.in_service	Block In Service

The recipe returns nothing when the lookup finds nothing, which costs no credits for this product, and stops with the error code and fix on a failed request.

Without code

If you do not want a shell job, use the generic HTTP request step of an automation platform: trigger when a lead is added to the list your PhoneBurner dialing uses, post its phone number to the LookValid endpoint with the key in the Authorization header, then add a second HTTP request that sends the state and rate center to the contact custom field route of the PhoneBurner REST API with your PhoneBurner bearer token. It needs no dedicated app.

REST and MCPOne shared credit balance

Questions

How many credits does a call list lookup use?

Each number spends credits at the carrier lookup rate shown on the pricing page, so a list costs that rate times its length.

Does it tell me the current carrier of a number?

No. It shows the carrier first assigned the block. A number that moved to another carrier still shows the original one, and it covers US numbers only.

Where do I store the key?

In the shell environment that runs the job, as LOOKVALID_API_KEY. PhoneBurner uses its own bearer token for its REST API, so keep the two separate and out of any shared script or list file.

Sources

PhoneBurner developer documentation: REST API route list https://www.phoneburner.com/developer/route_list, read 2026-10-18
LookValid API reference: Carrier Lookup (original carrier) https://lookvalid.com/docs/api/carrier-lookup, read 2026-10-18

LookValid is run by Meralume Labs. It is not connected to, endorsed by or a partner of any company or product named on this page, and every product name belongs to its owner.

LookValid bills every lookup in credits from one shared balance, so the same key works for each check above.

See Carrier Lookup (original carrier)