---
title: "Check domain availability"
method: POST
path: "/domain/lookup"
tags: ["Domain"]
---

# Check domain availability

`POST /domain/lookup`

## Request

- Base URL: `https://demo.onlinebillingform.com/api/v2`
- URL: `https://demo.onlinebillingform.com/api/v2/domain/lookup`
- Auth: HTTP bearer
- TypeScript: <https://skmtc.dev/billingserv/apis/billingserv-api-v2/docs/domain/lookup/post.ts> (a function with typed inputs; its response is checked against the schema)

Checks the configured registrar for the enabled domain extensions that match a name. Send the domain name without an extension, such as `billingserv`, to check up to 50 extensions. The endpoint is limited to 30 requests per minute per client.

## Request body

- DomainLookupRequest: Search for a domain name without its extension. The API normalizes surrounding whitespace and letter casing.
  - `domain` string, required: Domain name without an extension, such as `billingserv`. Do not include `.com` or another extension.
  - `limit` integer: Maximum number of enabled extensions to check.

## Response `200`

Availability results

- DomainLookupResponse
  - `success` true, required
  - `domain` string, required: Normalized domain name that was searched.
  - `registrar` string, required: Registrar used for this availability check.
  - `results` DomainAvailabilityResult[], required
    - `domain` string, required: Complete domain name checked by the registrar.
    - `extension` string, required: Domain extension, without a leading dot.
    - `available` boolean, required
    - `premium` boolean, required: Whether the registrar marked the domain as premium.

## Other responses

- `401`: Missing or invalid API key
- `403`: Authenticated key does not have permission for this endpoint
- `422`: Validation error
- `429`: Too many domain availability requests. Retry after the rate limit window.

## Changes

- **2026-08-22** `6b9208b64456`: 6 info
  - added the optional property `code` to the response with the `401` status
  - added the optional property `code` to the response with the `403` status
  - added the optional property `code` to the response with the `422` status
  - added the optional property `request_id` to the response with the `401` status
  - …2 more
- **2026-08-15** `f3171dce6f0f`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/billingserv/apis/billingserv-api-v2/changes/domain/lookup/post.md)

---

[API](https://skmtc.dev/billingserv/apis/billingserv-api-v2.md) - [All operations](https://skmtc.dev/billingserv/apis/billingserv-api-v2/llms.txt) - [OpenAPI document](https://skmtc.dev/billingserv/apis/billingserv-api-v2/revisions/232ab5ca8413?raw)