Please correct your number and select the corresponding country/region from the dropdown menu. Truecaller Phone Number Tracker is also available for the IOS version. When contacting WhatsApp, always send your phone number in full international format. Also known as country dial-in codes, these short number prefixes are assigned and managed by International Telecommunication Union (ITU) and defined in the ITU-T ISO. This article is a travel topic When calling a phone number in another country, there is usually a prefix you have to dial to indicate that you're placing an international call; this varies by country. Calls may be recorded and monitored for quality and training purposes. Gone are the days when phone numbers were as commonly memorized as street addresses. Country dialing codes are telephone number prefixes for reaching phone numbers in the networks of the other countries or regions. For Business users: To find a customer service phone number in your country, please click a region and find your country. The national conventions for writing telephone numbers vary by country.