--- title: "What is a user ID, and how do I discover one?" slug: "what-is-a-user-id-and-how-do-i-discover-one" tags: ["userId"] 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?sv=2026-02-06&spr=https&st=2026-11-09T05%3A50%3A11Z&se=2026-11-09T06%3A50%3A11Z&sr=c&sp=r&sig=MoLtdMVf7GSag8Yu%2ForGUTfYgfOwOlhLxGKSpC90i3s%3D) 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.