Who is in charge of area codes in the United States?

This responsibility is shared by Federal and state authorities. In the United States the North American Numbering Plan Administrator (NANP) is responsible for the administration, assignment and management of area codes. The FCC has jurisdiction over the telephone number administration. The FCC gives states the authority to decide when and how to introduce new area codes. This state authority is typically administered by the various state utility commissions.

Who is in charge of area codes in Canada?

In Canada the Canadian Number Administrator (CNA) provides numbering administration to the Canadian telecommunications industry. Canada participates in the North American Number Plan (NANP).

Who participates in the North American Numbering Plan?

The United States, Canada and a number of Caribbean nations.

How and why are new area codes introduced?

The demand for telephone numbers has increased with the growth of wireless telephones, fax machines and the use of additional lines in homes and businesses. As the number of telephone number is exhausted in a given area code a new area code must be added. New area codes are added either as an overlay or a geographic split.

What is an area code overlay?

In an overlay, the new area code has the same geographic boundary as the existing area code. Existing phone numbers and local calling scopes don't change, but 10-digit local dialing becomes necessary. Ten digit dialing is necessary because two different homes in the same geographic area can have the same seven digit phone number but each would have a different area code.

What is a geographic split?

A geographic split divides an area code into two or more areas with each area receiving its own area code. Although local calls from one area code into another require dialing 10 digits, your local calling range usually does not change.

What will happen if we use all the possible area code combinations?

The FCC will need to implement a new system of dialing. As an example the current model may need to be expanded by one or more digits. It does not appear that this will happen in the near future and the FCC has taken steps to use existing area codes more efficiently.

How do callers dialing ten digits know if they are making a toll call?

Telephone customers need to consult with their local phone company or check in the phone directory. The number of digits dialed does not determine if the call is free or a toll call.