# Signal House, free: Phone validation API

> Look up the carrier for a phone number. Always performs a fresh lookup (not cached). Billed per request.

Signal House's Free credit plan for the phone validation API costs $0.00 per 1,000 phones. We check each provider's docs for 9 fields. Signal House's docs list 4: Number, Type, Carrier, Porting and roaming.
In [our phone validation API benchmark](https://datacircle.dev/best-phone-validation-api.txt), the best plan from Signal House scores 60.7 out of 100. Signal House ranks 2nd of 58 providers.
This plan is free. We rank 1,330 plans for phone validation APIs by price. Half the plans cost $3.834 or less per 1,000 phones. [See the best free phone validation API plan.](https://datacircle.dev/best-phone-validation-api.txt)
[GuGuData's CNY 124 (about $19) monthly plan](https://datacircle.dev/validate-phone-apis/gugudata/cny-124-monthly/llms.txt) is the cheapest paid plan per 1,000 phones. GuGuData's CNY 124 (about $19) monthly plan charges nothing per call. You get as many phones as GuGuData's rate limit allows. [UAPI's CNY 4.90 pack](https://datacircle.dev/validate-phone-apis/uapi/cny-4-90-pack/llms.txt) costs the least for 10,000 phones a month: about $0.73.
[Trestle](https://datacircle.dev/validate-phone-apis/trestle/top-up-from-10-self-serve-pay-as-you-go-get-3-0-phone-intel-phone-validation-api/llms.txt), [Signal House](https://datacircle.dev/validate-phone-apis/signal-house/top-up-from-10/llms.txt) and [Data247](https://datacircle.dev/validate-phone-apis/data247/12-pack-membership-get-v3-0-verify247-phone/llms.txt) are the best phone validation API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/validate-phone-apis/signal-house/free
- [Phone validation API: the best of 50+ providers compared](https://datacircle.dev/best-phone-validation-api.txt)
- Get it: https://signalhouse.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Request: `POST https://v2.signalhouse.io/message/carrier-id`
- API key: with the plan, on https://signalhouse.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Its API docs: https://app2.signalhouse.io/docs/messages?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Sold by: Signal House (https://signalhouse.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing)
- Checked: 2026-11-09

## In the answer

- Completeness: 44%
- Number: ✓
- Type: ✓
- Carrier: ✓
- Porting and roaming: ✓

## Price

- $ per 1,000 phones: $0.00
- Per: call
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: POST /message/sms · POST /message/mms · POST /message/groupMessage · POST /message/rcs · POST /message/p2p · POST /number

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Look up the carrier for a phone number. Always performs a fresh lookup (not cached). Billed per request.

## Data

- Freshness: live
- What it checks: carrier
- Keep data: no limit
- Use data: You are granted a limited, non-exclusive, non-transferable, and revocable license to use the Services for your internal business purposes. [...] You shall not use the Platform, or any information derived from the Platform, to design, develop, build, replicate, enhance, or assist in the creation of any product, service, workflow, platform, or system that is competitive with or substantially similar to the Platform or any of its components, whether for internal use, commercial use, or for the benefit of any third party. [...] Except for the limited right to use the Services for their intended internal business purposes in accordance with these Terms, you shall not, and shall not permit any third party to: Copy, reproduce, duplicate, republish, scrape, download, distribute, display, or create derivative works from any Platform Materials. [...] Use any information learned from access to the Services to build, improve, advise on, or support any competing product or service.

## Plan

- Pay: $0
- You get: $25
- Enough for: 5,000 calls, once

## Rate limit

- Batch: 1

## Speed

- Answer: in the call
- Median: 0.34 s

## The call

- You send: phoneNumber
- Method: POST
- Path: /message/carrier-id

## About the plan

- Plan: Free credit
- Who can get it: anyone who creates an account

## The 8 fields the plan's answer can hold

number, carrier name, carrier family, carrier region, ported, line type, degraded confidence, lookup cost

## Signal House's plans (3)

- [Signal House, free](https://datacircle.dev/validate-phone-apis/signal-house/free/llms.txt): $0.00 per 1,000, 44% complete, live
- [Signal House, top-up from $10](https://datacircle.dev/validate-phone-apis/signal-house/top-up-from-10/llms.txt): $5.00 per 1,000, 44% complete, live
- [Signal House, contact us](https://datacircle.dev/validate-phone-apis/signal-house/contact-us/llms.txt): 44% complete, live

## Signal House's calls (1)

- `POST /message/carrier-id`: [Signal House, free](https://datacircle.dev/validate-phone-apis/signal-house/free/llms.txt)

## Signal House's APIs (1)

- [Signal House: phone validation API pricing, 3 plans](https://datacircle.dev/validate-phone-apis/signal-house/free/llms.txt)

## Signal House: phone validation API alternatives

- [CallerAPI, $25 monthly, Basic, GET /api/network-lookup/{phone}](https://datacircle.dev/validate-phone-apis/callerapi/25-monthly-basic-get-api-network-lookup-phone/llms.txt): $5.00 per 1,000, 44% complete, live
- [ProWebLook, $250 pack, WhatsApp One-Time 50K, GET /wavalidation](https://datacircle.dev/validate-phone-apis/proweblook/250-pack-whatsapp-one-time-50k-get-wavalidation/llms.txt): $5.00 per 1,000, 67% complete, live
- [iBlueText, top-up, Pay-as-you-go lookup credits](https://datacircle.dev/validate-phone-apis/ibluetext/top-up-pay-as-you-go-lookup-credits/llms.txt): $5.00 per 1,000, 11% complete, live
- [SignalWire, top-up from $5, Prepaid balance, GET /api/relay/rest/lookup/phone_number/{e164_number}, Look up phone number](https://datacircle.dev/validate-phone-apis/signalwire/top-up-from-5-prepaid-balance-get-api-relay-rest-lookup-phone-number-e164-number-look-up-phone-number/llms.txt): $5.00 per 1,000, 67% complete, live

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-09.

- https://app2.signalhouse.io/docs/billing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://app2.signalhouse.io/docs/messages?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://signalhouse.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://signalhouse.io/pricing.md?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://signalhouse.io/terms-and-conditions?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing