---
page_type: error
code: 80623
message: "80623: Duplicate Participant Request"
level: ERROR
product: Proxy
---

## Description

Possible duplicate Participant created in multiple Sessions.

### Possible Causes

A request to create a Participant for an Identifier was made while another ongoing request was in progress for the same Identifier in a different Session. This can result in the same proxy identifier being assigned in multiple sessions for the same Identifier, causing incorrect behavior.

### Possible Solutions

If you need to add the same person to multiple Sessions, ensure that the Participant Create requests are made one at a time. To allow Proxy to enforce this, please pass the ReturnErrorOnDuplicateRequest=true parameter in your Participant Create requests and/or Session Create requests (if participant parameters are included). This will be the default behavior for all requests in the future, and will enable us to use more efficient logic to find ProxyIdentifiers for your participants, thus reducing Participant Create latency.