In the following doc: https://support.twilio.com/hc/en-us/articles/223181828-Does-Twilio-check-to-see-if-phone-numbers-can-receive-SMS-
It is stated "In countries without a "mobile range" like the United States, Canada and most Caribbean nations, there is currently not a reliable way to determine if a phone number is a mobile number or not." Is this statement incorrect?
Reading Twilio Lookup docs it seems like it is easy to identify if a US number is mobile or landline: https://www.twilio.com/docs/lookup/api
I tried a couple US numbers and got an indication of the type be it mobile or landline number. However I just tried another US number in Twilio console and got no result and the following error message "We were unable to complete your Lookup query. Please try again later or contact support." Anybody aware of the limitations that may exist with the Twilio lookup API
The Twilio documentation is correct. They are referring to determining the number capabilities type based on the number pattern and range, rather then using another tool like the Twilio Lookup API to do so.
The Twilio Lookup API is designed to tell you the number type [VoIP, Mobile, or Landline] when doing a carrier lookup on that specific number.
The error you got in the Lookup API, may indicate you entered an invalid phone number, not assigned to any carrier/OCN (Operating Company Number).