# MailSlurp, free: Phone validation API

> Verify validity of a phone number

MailSlurp's phone validation API on its Free plan. It costs $0.00 per 1,000 phones. MailSlurp's docs list 3 of the 9 key fields we check: Number, Validity, Place.
We haven't run MailSlurp through [our phone validation API benchmark](https://datacircle.dev/best-phone-validation-api.txt) yet.
This plan is free. We rank 1,097 plans for phone validation APIs by price. Half the plans cost $2.998 per 1,000 phones or less.
[GuGuData's CNY 124 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 monthly plan charges nothing per call. You get as many phones as GuGuData's rate limit allows.
[Data247](https://datacircle.dev/validate-phone-apis/data247/12-pack-membership-get-v3-0-verify247-phone/llms.txt), [Abstract API](https://datacircle.dev/validate-phone-apis/abstract-api/19-monthly-starter-5000-requests-month/llms.txt) and [Foxentry](https://datacircle.dev/validate-phone-apis/foxentry/top-up-pay-as-you-go-post-phone-validate-validate-phone-number-extended/llms.txt) are the best phone validation API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/validate-phone-apis/mailslurp/free
- [Phone validation API: the best of 40+ providers compared](https://datacircle.dev/best-phone-validation-api.txt)
- Get it: https://app.mailslurp.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Request: `POST https://api.mailslurp.com/phone/validate`
- API key: with the plan, on https://app.mailslurp.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Its API docs: https://docs.mailslurp.com/api/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing#validatePhoneNumber
- Sold by: MailSlurp (https://www.mailslurp.com?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing)
- Checked: 2026-11-06

## In the answer

- Completeness: 33%
- Number: ✓
- Validity: ✓
- Place: ✓

## Price

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

## Aggregators

- Aggregators: none

## Charges

- Also pays for: Create an inbox email address: 100 inboxes a month

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Verify validity of a phone number

## Data

- Keep data: no limit
- Use data: You must not, directly or indirectly: use the Services for unsolicited communications, spam, or mass messaging in violation of applicable law [...] resell, sublicense, or make the Services available to third parties except as expressly permitted [...] use the Services or any data obtained from the Services to train, retrain, or improve any machine learning models or artificial intelligence systems (including large language models) without MailSlurp's express prior written consent.

## Plan

- Pay: $0

## Rate limit

- Per second: 150
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: phoneNumber
- Method: POST
- Path: /phone/validate

## About the plan

- Plan: Free
- Who can get it: anyone, 1 user, no card needed

## The 5 fields the plan's answer can hold

country code, country prefix, phone number, valid, validation errors

## MailSlurp's plans (5)

- [MailSlurp, free](https://datacircle.dev/validate-phone-apis/mailslurp/free/llms.txt): $0.00 per 1,000, 33% complete
- [MailSlurp, $19.99 monthly](https://datacircle.dev/validate-phone-apis/mailslurp/19-99-monthly/llms.txt): 33% complete
- [MailSlurp, $69 monthly](https://datacircle.dev/validate-phone-apis/mailslurp/69-monthly/llms.txt): 33% complete
- [MailSlurp, $199 monthly](https://datacircle.dev/validate-phone-apis/mailslurp/199-monthly/llms.txt): 33% complete
- [MailSlurp, contact us](https://datacircle.dev/validate-phone-apis/mailslurp/contact-us/llms.txt): 33% complete

## MailSlurp's calls for this API (1)

- `POST /phone/validate`: [MailSlurp, free](https://datacircle.dev/validate-phone-apis/mailslurp/free/llms.txt)

## MailSlurp's APIs (2)

- [MailSlurp: email verification API pricing, 5 plans](https://datacircle.dev/validate-email-apis/mailslurp/free/llms.txt)
- [MailSlurp: phone validation API pricing, 5 plans](https://datacircle.dev/validate-phone-apis/mailslurp/free/llms.txt)

## MailSlurp: phone validation API alternatives

- [Abstract API, free](https://datacircle.dev/validate-phone-apis/abstract-api/free/llms.txt): $0.00 per 1,000, 89% complete, 1 day
- [Foxentry, free trial, POST /phone/validate, Validate phone number (basic)](https://datacircle.dev/validate-phone-apis/foxentry/free-trial-post-phone-validate-validate-phone-number-basic/llms.txt): $0.00 per 1,000, 56% complete, stored
- [HLR Lookups, free, 100 free lookups, POST /nt-lookups](https://datacircle.dev/validate-phone-apis/hlr-lookups/free-100-free-lookups-post-nt-lookups/llms.txt): $0.00 per 1,000, 67% complete, stored
- [seven.io, free test credit, GET /api/lookup/hlr](https://datacircle.dev/validate-phone-apis/seven-io/free-test-credit-get-api-lookup-hlr/llms.txt): $0.00 per 1,000, 78% complete, live
- [Ideal Postcodes, free](https://datacircle.dev/validate-phone-apis/ideal-postcodes/free/llms.txt): $0.00 per 1,000, 44% complete

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-06.

- https://api.mailslurp.com/v2/api-docs/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://app.mailslurp.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://docs.mailslurp.com/api/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://www.mailslurp.com/guides/avoiding-api-rate-limits?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://www.mailslurp.com/terms-and-conditions/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing