Telephone country code 43 is reserved for the country of Austria. This code allows someone to call Austria from another country by dialing 43 after the International Dialing Prefix.
The standardization of country calling codes is regulated by the Telecommunication Standardization Sector of the International Telecommunication Union, commonly referred to as the ITU-T. It produces international standards known as the ITU-T Recommendations that define key elements necessary for global information sharing and communication. These recommendations are not mandatory, but most countries adopt them as law to facilitate efficient international communication.
In Austria, there are no standard lengths for area codes or phone numbers, and some subscriber numbers can be as short as three digits.