Area Code 21 (+99421 / 01199421 / 0099421)
Where does the area code 21 come from? (+99421 / 01199421 / 0099421, Azerbaijan)
The prefix 21 is the area code for Shirvan. For the fictitious phone number 7157456 and the area code 21 the number to dial is 21 7157456. And Shirvan is located in Azerbaijan.
The area code prefix assigns the phone number of a subscriber to a specific location. Other types of prefix exist in addition to the area code: International country prefixes, the prefixes of mobile phone providers and the prefixes of various services. These are combined to suit several purposes. When calling from one country to another in cases where the recipient of the call has a landline, the country prefix is combined with the area code and the number of the subscriber. For the fictitious phone number 7157456, the area code 21 (Shirvan) and the Country code 011994 the number to dial is 011994 21 7157456. If the call is to a mobile device, the Country code is combined with the mobile service provider's prefix and the number of the subscriber. If a call is made to a subscriber in the same country, the Country code can be omitted. In the case of national calls from one landline to another, the area code can also be omitted in many countries when both subscribers have the same area code. Particularly in countries where subscribers are able to keep the same telephone number after moving to another location or city, the area code – in this case 21 – must of course also be dialled.
Both the country prefix and the area code prefix have one or more digits before the actual prefix. These digits indicate to the telephone exchange that the following digits are an area code or a Country code and not the actual phone number. In the case of area codes, this is usually a zero. In the case of Country codes, Western European countries and most countries in Africa, South America and the Middle East follow the ITU recommendation to use two zeros. However, some countries do not adhere to this recommendation: For example, the countries that participate in the North American numbering scheme use 011, and Japan uses 010.
Services that are accessed through service prefixes may incur charges not only from telecommunication companies, but also from the companies that offer these services. As a result, a number of dubious companies offer services that are of little use but incur high fees. In order to increase their profits still further, such services attempt to keep callers on the line for as long as possible. The supervisory authorities regularly take action against such providers, but that cannot be relied upon. In addition to special numbers that can be identified by means of their prefixes, there are also speed-dial numbers. The most well-known are the emergency number 112 in Europe and 911 in North America. These numbers can be used nationwide and need no prefixes, i.e. no Country code +994 (011994) or area code 21 (Shirvan).
As a general rule, the caller's telephone number is transmitted to the recipient of the call and shown on the display. Although it is possible to suppress your own telephone number, which makes sense in terms of data protection, it should come as no surprise if the person that you are calling does not accept the call. Many people want to know who is calling them and do not accept anonymous calls.
If you are outside United States of America and you want to call a person in Shirvan, in addition to the area code, you need the Country code for the country you wish to call. The Country code for United States of America is +994 (011994), so if you are in United States of America and you want to call a person in Shirvan, you have to prefix that person’s phone number with +994 21. The zero in front of the area code is omitted in this case. For the fictitious phone number 7157456, the area code 21 (Shirvan) and the Country code 011994 the number to dial is 011994 21 7157456.