Twilio will return this error code if a resource is currently unavailable. Please wait a few moments and then try the request again. We apologize for the inconvenience.
If you are seeing a consistent pattern of 503 server errors coming from the Twilio API, check our status page for more details. If our status page has no information, contact firstname.lastname@example.org with details about the requests that are failing, and we will investigate.
This error code indicates the request is safe to retry at a later time.