Area codes are a staple in telecommunication. Everyone has had to make a long distance phone call at one point or another and when that happens you have to dial in the area code. Area codes have been around since 1947. If you’ve ever been curious about how area codes work, here’s what you need to know.

In the United States

Area codes help phone systems route calls to specific regions, both within the United States and around the world. In the U.S., area codes are three-digit numbers that start each phone number, like (555) 123-4567. Introduced in 1947, they allow calls to connect directly to regions without needing an operator. Major cities, like New York with area code 212 and Los Angeles with 310, often have multiple area codes due to high demand for new numbers. When a single area needs more numbers, new area codes are added, either through “splits,” which create new codes for separate areas, or “overlays,” where new codes are added on top of the existing ones.

In the U.S., the structure of area codes is managed by the North American Numbering Plan (NANP), which keeps phone numbers organized. These area codes begin with a number from 2 to 9, followed by a 0 or 1, with the last digit being any number. Larger cities might have several area codes, like New York, which uses codes such as 212, 718, and 917, while rural areas may only need one. The system’s flexibility helps keep up with the growing need for phone numbers, especially as more people use cell phones.

Beyond the US

Outside the United States, area codes vary widely by country and can look quite different. For example, in Germany, area codes can have two to five digits, depending on the location, and are part of the European Numbering Plan. In the United Kingdom, area codes also vary in length, with some codes shorter or longer based on region and population. This variation reflects the unique needs and systems of different countries, as each has its own way of organizing phone numbers.

In regions like Asia and South America, area codes also follow distinct rules. Japan’s area codes, for instance, range from one to four digits, with larger cities usually having shorter codes to make more numbers available. To dial internationally, callers must enter the country code first, followed by the area code and local number. This structure ensures that calls connect smoothly across countries, keeping global communication organized and efficient.