Phone number formats vary from country to country. In the United States, phone numbers are ten digits, including the area code. In Norway, phone numbers are eight digits; at one time there was a two-digit area code for metropolitan areas, but this has been discontinued. Also, the layout and punctuation of phone numbers change from country to country.

The following examples show the same phone number in a variety of formats:

Each of the previous examples is an acceptable phone number format. You should always design phone number fields to accommodate appropriate formats.