---
title: "What is a user ID, and how do I discover one?"
slug: "what-is-a-user-id-and-how-do-i-discover-one"
updated: 2024-09-20T14:36:57Z
published: 2024-09-20T14:36:57Z
canonical: "support.lusid.com/what-is-a-user-id-and-how-do-i-discover-one"
---

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

# What is a user ID, and how do I discover one?

LUSID automatically generates a unique ID for every user, whether [personal or service](/v1/docs/what-are-a-personal-user-and-a-service-user).

You may need to know a user's ID to perform a particular operation, for example [setting up an automated activity](/v1/docs/setting-up-a-schedule-subscription-or-other-activity-on-behalf-of-a-service-user) on behalf of a service user, or [filtering entities created or modified](/v1/docs/filtering-information-retrieved-from-lusid#filtering-entities-based-on-version-informationchange-history) by a particular user.

Assuming you have appropriate permissions, you can discover user IDs by navigating to the **Identity and Access > Users** dashboard in the [LUSID web app](https://www.lusid.com/app/home):

![](https://cdn.document360.io/d575ad81-c0ed-4980-bbd1-d59ac5c3de82/Images/Documentation/4d9672ee-846c-4daf-8a05-2866e93894ba.png)

Alternatively, you can call the [ListUsers](https://www.lusid.com/docs/api/identity/endpoints/users/ListUsers) API:

```json
[
  {
    "id": "00ubs2temhwlYz2lI2p7",
    "emailAddress": "john.doe@acme.com",
    "login": "john.doe@acme.com",
    "firstName": "John",
    "lastName": "Doe",
    "type": "Personal",
    "status": "PROVISIONED",
    "external": false,
    ...
  },
  {
    "id": "00ubk5b5apJVhOlAg2p7",
    "emailAddress": "jane.doe@acme.com",
    "login": "jane.doe@acme.com",
    "firstName": "Jane",
    "lastName": "Doe",
    "type": "Personal",
    "status": "PROVISIONED",
    "external": false,
    ...
  }
]
```

Conversely, if you know a user's ID and want to discover more information about them, call the [FindUsersById](https://www.lusid.com/docs/api/identity/endpoints/users/FindUsersById) API.