In the United States, telephone area codes do not cross state lines. However, within a state, there are many cases where a telephone area code boundary divides a city or town between two or more area codes.
The only states left that have only one area code each are Alaska, Hawaii, Idaho, Montana, Wyoming, North Dakota, South Dakota, Delaware, Rhode Island, Vermont, New Hampshire, and Maine. In addition, the entire state of West Virginia is an overlay; although there are two area codes, there is no boundary between them, since they both serve the entire state.
The first area code overlay in the United States was area code 917 for New York City. In the original plan, 917 was to be the area code for mobile phones and pagers, with mobile users in the 212 and 718 area codes (then the only two area codes for New York City) forced to move their numbers to 917. However, federal regulators held that it was illegal to discriminate on the basis of class of service (i.e., landline versus cellphone, etc.) in deciding who got the desirable 212 and 718 numbers and who got the less-desirable 917 numbers. The next overlays in the United States were in Maryland in 1997. However, since 2007, there have been no area code splits, only overlays. Canada has had only overlays since 1999. Thus, there are more and more parts of the North American Numbering Plan (the area code system that serves the USA, Canada, and 18 assorted island nations and territories, mostly in the Caribbean) that have two or more area codes for the same location.
Birmingham is the biggest city. Montgomery is the state capital. 205,215,256, and 334 are the area codes.
The 972 area code is one of the three area codes that is used in the city of Dallas, Texas. The other area codes used in the city of Dallas are 214 and 609.
In the United States, area codes do not cross state lines, but they do not necessarily follow city or county limits or any other political boundaries.
In 2009 the area code 773 stopped being in use for the city of Chicago. Instead the state employed a wider area code for the city and its suburbs rather than using two or more area codes for the full area.
60615 is not an area code. Area codes in the US are 3 digits and are used with telephone numbers. The postal ZIP Code 60615 is for Chicago, IL.
Oklahoma has four area codes: 405: Oklahoma City 580: Enid, Ada, Lawton, most of the state 918: Tulsa 539: (overlay of 918)
There are several postal codes for Ibadan. Ibadan being a very large city has postal codes like 200001 for Dugbe Area, 200002 for Molete, etc.
The first area codes were introduced in the United States and Canada by the Bell System in 1947. There were 86 codes in the initial assignment, including 212 for New York City, 213 for Los Angeles, and 305 for the entire state of Florida.
the city and state code enforcers
Boston is a city, and it is in the state of Massachusetts. As you note in your question, 02116 is a zip code, a postal code that tells in which part of the city a neighborhood or area is located. Because Boston is a big city with many neighborhoods, it has a number of zip codes. 02115 and 02116 are two zip codes in the "Back Bay" section of Boston.
city-state
one of them is 347 if its co op city new york