Potato_PhoneMask

Phone Mask is a simple Magento extension that helps customers to input phone number easier at checkout. Auto-Formatted phone numbers. Your customers don't have to input parentheses, spaces and dashes anymore.
No need to modify templates. Javascript only - the extension does not use any additional libraries.Mask is defined by store administrator, that governs what a user is allowed to enter in as input. It can be said to be a template, or set format that entered data must conform to, mainly used for the purposes of data integrity by preventing transcription errors.
e.g. When entering a phone number on a data capture form, in the format "(___) ___ - ____" the area code brackets, the space between the number and the area code will automatically be placed in.

Features

Simplifies Magento checkout. Customer don't have to input parentheses, spaces and dashes.
Mainly used for the purposes of data integrity by preventing transcription errors. All phone numbers will be of the same format. Say goodbye to obscurity.
Lifetime free support, bugfixes and updates
Installation service included