The Telephone module allows you to create fields that contain telephone numbers.
It depends on the Field and the Field UI modules.
As with other fields a telephone field can be added to any bundle. This means you can add a telephone field to a user, a content type (news, event) or custom block.
Telephone is included in Drupal 8 but a Telephone backport for Drupal 7 exisits
Managing and displaying telephone fields
The settings and the display of the telephone field can be configured separately. See the Field UI help for more information on how to manage fields and their display.
Displaying telephone numbers as links
Telephone numbers can be displayed as links with the scheme name tel: by choosing the Telephone display format on the Manage display page. Any spaces will be stripped out of the link text.