{% note tip "" %}
If you are developing integrations for Bitrix24 using AI tools (Codex, Claude Code, Cursor), connect to the MCP server so that the assistant can utilize the official REST documentation.
{% endnote %}
The authorization server oauth.bitrix.info returns the error code in the error field and the explanation in the error_description field. The error arrives instead of a pair of tokens — either when exchanging the authorization code or when renewing the tokens.
{
"error": "PAYMENT_REQUIRED",
"error_description": "Payment required"
}#|
|| Code | Description | What to Do ||
|| invalid_request | An incorrectly formatted authorization request was provided | Check the composition and spelling of the request parameters ||
|| invalid_client | Invalid client data was provided. The application may not be installed in Bitrix24 | Check client_id and client_secret, and make sure that the application is installed in this Bitrix24 ||
|| insufficient_scope or invalid_scope | Access permissions requested exceed those specified in the application card | Add the missing permissions to the application card ||
|| invalid_grant | Invalid authorization data was provided for obtaining access_token. This occurs both when tokens are obtained for the first time and when they are renewed | If refresh_token has expired, go through the authorization again using the complete protocol ||
|| PAYMENT_REQUIRED | The trial or paid period of the application has expired | Renew the application payment. Until then, the authorization server will not issue tokens ||
|#
The errors that Bitrix24 itself returns on method calls — for example, expired_token for an expired access_token — are collected in the general list Error Codes.