In Contacts, if you would like to add a non-US-based telephone number you can by using the formatting below. 

• If entering + country code, the rest of the number, and it’s a valid International number this is supported. We use Google's phone validation library to validate these numbers.
  • Example of the format: +111 (11) 111 1111
• Numbers starting with 0 is always a local dialling indicator and the Google phone library doesn’t support these numbers.