---
title: "Check login ID"
slug: "management-subaccount-checkloginid"
tags: ["Sub Account"]
updated: 2026-09-17T10:05:32Z
published: 2026-09-17T10:05:32Z
canonical: "api.ncloud-docs.com/management-subaccount-checkloginid"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://api.ncloud-docs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Check login ID

Available in Classic and VPC

Check the validity and duplication of the login ID to be used for a sub account.

## Request

This section describes the request format. The method and URI are as follows:

| Method | URI |
| --- | --- |
| GET | /api/v1/join/check-login-id |

### Request headers

For information about the headers common to all Sub Account APIs, see [Sub Account request headers](/docs/en/management-subaccount#%EC%9A%94%EC%B2%AD%ED%97%A4%EB%8D%94).

### Request query parameters

You can use the following query parameters with your request:

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `loginId` | String | Required | Sub account login ID - Enter 3-30 characters by combining uppercase/lowercase English letters, numbers, and special characters "-", "_", ".", and "@". - First letter must be an English uppercase or lowercase letter. |

### Request example

The request example is as follows:

```
curl --location --request GET 'https://subaccount.apigw.ntruss.com/api/v1/join/check-login-id?loginId=subaccount' \
--header 'x-ncp-apigw-timestamp: {Timestamp}' \
--header 'x-ncp-iam-access-key: {Access Key}' \
--header 'x-ncp-apigw-signature-v2: {API Gateway Signature}' \
--header 'Accept: application/json'
```

## Response

This section describes the response format.

### Response body

The response body includes the following data:

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `success` | Boolean | - | Sub account login ID check result - `true` \| `false` - `true`: Available ID - `false`: Unavailable ID |
| `message` | String | - | Reason for unavailability - Display if `success` is `false` |

### Response status codes

For information about the HTTP status codes common to all Sub Account APIs, see [Sub Account status codes](/docs/en/management-subaccount#%EC%9D%91%EB%8B%B5%EC%83%81%ED%83%9C%EC%BD%94%EB%93%9C).

### Response example

The response example is as follows:

#### If the check shows that the ID is available

The following is a sample response if the check result is an available ID.

```
{
    "success": true,
    "message": ""
}
```

#### If the check shows that the ID is unavailable

The following is a sample response if the check result is an unavailable ID.

```
{
    "success": false,
    "message": "English letters, numbers, and special characters ".", "@", "-", and "_" are allowed. Enter a string that begins with an English letter and is between 3 and 60 characters long."
}
```