telephone_validation
Security covered
Telephone validation module provides field validation to Drupal core Telephone field and tel form element. Just install the module and enable field validation to ensure telephone data quality.
The module uses libphonenumber composer package for validation, and supports the many different national number formats. For international telephone field we suggest using E164 format.
D8 version works well with both Form API and Field API so you can validate data on form level or field validation level (which is important if you create or update data via REST API).
If you have any troubles using this module please create an issue.
For formatting the telephone number use telephone_formatter module.