Phone number normalization: Any pre-existing libraries?

Question

I have a system which is using phone numbers as unique identifiers. For this reason, I want to format all phone numbers as they come in using a normalized format. Because I have

Answer 1

You could use libphonenumber from Google. Here's a blog post:

http://blog.appharbor.com/2012/02/03/net-phone-number-validation-with-google-libphonenumber

Parsing numbers is as easy as installing the NuGet package and then doing this:

var util = PhoneNumberUtil.GetInstance();
var number = util.Parse("555-555-5555", "US");

You can then format the number like this:

util.Format(number, PhoneNumberFormat.E164);

libphonenumber supports several formats other than E.164.