# 91000: Cannot enter presence without a clientId

Identifier: `cannot_enter_presence_without_a_client_id`



A request to enter the presence set was rejected because the connection had no clientId. Presence members are identified by their clientId, so one is required to enter.

## What you should do

Give the client a [client ID](https://ably.com/docs/auth/identified-clients.md) before it enters presence. Set one when the client authenticates, either in the client options or in the token issued to it, or enter on behalf of a specific client ID with `enterClient()`.

## Why it happens

The client tried to enter the presence set without a client ID. A connection has no client ID when it authenticates with Basic authentication, or with a token whose client ID is a wildcard, and none was set in the client options.

## What you'll see

The error is reported with code 91000 and HTTP status 400. The message is of the form `unable to enter presence channel (no clientId)`.