HTTP Response Codes & Errors

Codes summary

A summary of HTTP Response Codes returned by the Projects API is shown below.
HTTP Code Summary Description
200 OK Successful API call. Learn more
201 Created Resource Created.
204 No Content The server has successfully fulfilled the request and that there is no additional content to send in the response.
400 Bad Request A bad request or a validation exception has occurred.
401 Unauthorized Invalid authorization credentials or organisation hasn’t been provisioned in Xero Projects.
404 Not Found The resource you have specified cannot be found
500 Internal Error An unhandled error with the Xero API. Contact the Xero API team if problems persist
503 Rate Limit Exceeded The API rate limit for your organisation/application pairing has been exceeded. Learn more
503 Not Available API is currently unavailable – typically due to a scheduled outage – try again soon. Learn more

Common response codes


The Projects API will return with a:

  • HTTP 200 for successful GETS
  • HTTP 201 for successful modifications with content in the response, and
  • HTTP 204 for successful requests with no content

HTTP 400 Bad Request

HTTP 400 responses includes a "message" describing the error and a modelState object describing which elements of the request caused the error.

    "message": "The request is invalid.",
    "modelState": {
        "model.Name": [
            "The Project Name cannot be empty"
        "model.ContactId": [
            "The ContactId cannot be null or empty"

HTTP 401 Unauthorized

A customer may disconnect your application from within Xero at anytime so at the very least you should implement functionality to handle a 401 error and allow a customer to easily reauthorize your application.

A description of the reason for the error is returned in response using the following format.
Learn more about unauthorized errors

HTTP 503 Rate Limit Exceeded

An application can make up to 5000 API calls against a particular Xero organisation in a rolling 24 hour period and 60 calls against a particular Xero organisation in a rolling 60 second period. The following will be returned in the body if you exceed a rate limit.
Learn more about limits

HTTP 503 Not Available

From time to time we might require a short outage to carry out maintenance or upgrades. In most cases the Xero API will respond with a HTTP 503 when it is not available, and provide one of the following response bodies:
The Xero API is currently offline for maintenance
The Xero API is temporarily unavailable

HTTP 503 Organisation Offline

A specific organisation may not be available though the Xero APIs themselves are online. In this instance, the below response will be returned. Typically this situation may occur for several minutes. A retry interval of 5mins or so is recommended.
The Organisation is offline