Turkey's area codes were updated in 1988 with the transition to a 12-digit system. PTT modeled this after the system used in the USA. In 1947, AT&T determined city-specific codes; the most crowded centers like New York were given low-digit codes like "212" that could be dialed quickly on rotary (dial) phones. The combination that mechanically steals the least time from the line, occupies the switchboard the least, and tires the user's finger the least is 212.
PTT while bringing this system to Turkey, applied the "212" code given to New York in the USA to Istanbul, the most densely populated city, and gave Ankara the code for Chicago, 312. Moreover, in terms of the technology of the period (tone dialing), there was actually no technical necessity for this system; PTT preferred this numbering while distributing codes to cities according to population size. These first codes were also etched in minds as "elite" codes because they were where the country's wealthiest people were located. In 1995, considering the increasing population, the Anatolian side switched to 216.
In the USA, because mobile operators also use city codes, these first codes filled up over time and additional codes were defined for cities, such as 646 and 332 for New York. In Turkey, due to the definition of separate codes for mobile operators, the assignment of separate codes to the European and Anatolian sides of Istanbul, and the decrease in demand for landlines over time, the need to "fill the code" and "get an additional code" never arose.
Telephone codes of Turkish cities
Another factor in Turkey's coding is longitude. Codes starting with 2 were given to western provinces, 3 to central parts, and 4 to eastern parts. Also, starting with 0 served as a prefix signaling the switchboard "I am calling outside the city, not within the city." Codes containing 0 and 9 were assigned to places with very low populations (so that good numbers would remain for other cities).
From the USA, a few more interesting facts: No area code starts with 0 or 1 because switchboard equipment could misinterpret the leading 1, and thought 0 was a request to connect directly to the operator. Also, the 555 code is not used anywhere; it is reserved for the entertainment industry. That's why we see this code in all TV series and movies. Its purpose is simple: those who see the number and are curious will not reach anywhere when they call.
Today, although we live in an era where we almost never use area codes thanks to smartphones, codes like 212 and 312 continue to remain as geographical and class signatures left by the analog era to the digital world.
