(See related links)
Area codes in the US and Canada were introduced in 1947.
Area code +44 121 is Birmingham, England, United Kingdom There is no North American (US, Canada, etc.) area code +1 121; North American area codes never begin with 1. There are several +1 21X area codes, all in the US.
There is a list of area codes for the US and Canada on LincMad.com; see the related link.
The US and Canada began using area codes in 1947.
One can find area codes at their local post office. The post office always has these on hand, and they will be happy to bring it out and show it to you.
The US and Canada began using area codes in 1947.
The country code for the United States, along with Canada and a variety of Caribbean and nearby islands, is +1. Cellphones in the US do not have any special area codes. They use the same geographic area codes as landlines.
There are about 300 area codes in the United States, about 30 in Canada, and about 20 in other miscellaneous islands in or near the Caribbean that share country code +1 with the US and Canada. There are about 400 area codes in Mexico. There are about 600 area codes in the UK. There are about 5,200 area codes in Germany.
Mexico has about 400 area codes. Ask a more specific question.
There are many area code listings on the internet.
512 is one of the area codes for the area surrounding Austin, Texas. Area codes in the US are not specific to cell phones or land lines.
There are several dozen area codes in Brazil. Please be more specific.