If you make a phone call to a foreign number, you need a particular code added in front of the number. It is called the international dialing code or telephone country code, a one- to three-digit code starting with a plus (+) sign.

People do not always remember their country code correctly, so you may need to assist them when you ask for their international telephone number. Fortunately, with the help of the Listo plugin, you can easily implement telephone country code suggestions in Contact Form 7.