Twilio's Lookup API currently only handles a single request per phone number. If you have a batch of several phone numbers you would like to lookup, we recommend that you make multiple requests to Twilio's API.
Notice: Responses to your requests containing
HTTP 429 or Error code 20429 indicate that you have hit the API request concurrency limit. For more information, see Twilio API response Error 429 "Too Many Requests".