# Obtain entity identifiers (Entity GUID)
source: https://developer.mastercard.com/iccp/documentation/03_use-cases/entity-identifier/index.md

This API supports the following use cases for obtaining entity identifiers:

## Obtain entity identifiers {#obtain-entity-identifiers}

* [Obtain your entity identifier](https://developer.mastercard.com/iccp/documentation/03_use-cases/entity-identifier/index.md#obtain-my-entity-identifier)
* [Obtain descendant entity identifiers](https://developer.mastercard.com/iccp/documentation/03_use-cases/entity-identifier/index.md#obtain-descendent-entity-identifiers)

## Obtain my entity identifier {#obtain-my-entity-identifier}

In order to register a Real Card and conduct any further operations, an entity identifier, also known as an `ownerGUID` or `entityGUID` is required. You can obtain the identifier for your organization using the Entities API.
Diagram get-your-id
API Reference: `GET /entities`

## Obtain descendent entity identifiers {#obtain-descendent-entity-identifiers}

If your entity has any descendant entities registered, you can obtain their identifying entity `GUIDs` using the endpoint below. It is important that Real Card registration is associated with the correct entity in the hierarchy.

API Reference: `GET /entities/{entity_guid}/descendants`

Diagram get-descendant-id