Area code 670 is the telephone

area code A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, rea ...

in the

North American Numbering Plan The North American Numbering Plan (NANP) is an integrated telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1, World Numbering Zone ...

(NANP) for the U.S.

Commonwealth of the Northern Mariana Islands The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI), is an unincorporated territory and commonwealth of the United States consisting of 14 islands in the northwestern Pacific Ocean.Lin, Tom C.W.Amer ...

(CNMI). It was created with a

permissive dialing In North America, permissive dialing is the ability to make phone calls in an area subject to a newly introduced area code by using both the new and preexisting dialing methods. When an area is given a new area code under a split plan, the area's ...

period from July 1, 1997 to July 1, 1998, when it permanently replaced the previous

International Telecommunication Union The International Telecommunication Union (ITU)In the other common languages of the ITU: * * is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information ...

(ITU) country code

670 __NOTOC__ Year 670 ( DCLXX) was a common year starting on Tuesday of the Julian calendar, the 670th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 670th year of the 1st millennium, the 70th year of the 7th century, and ...

. Country code 670 was later assigned to

East Timor Timor-Leste, also known as East Timor, officially the Democratic Republic of Timor-Leste, is a country in Southeast Asia. It comprises the eastern half of the island of Timor, the coastal exclave of Oecusse in the island's northwest, and ...

History

Although the Northern Mariana Islands (NMI) became a commonwealth in 1978 and the United States assumed sovereignty in 1986, calling from the United States to CNMI remained an international call (011-670-xxx-xxxx). After the CNMI was added to the North American Numbering Plan, the U.S.

Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wire, internet, wi-fi, satellite, and cable across the United States. The FCC maintains j ...

(FCC) regulated calls between the U.S. and CNMI as "domestic", causing a reduction in the cost of telephone calls and making NANP toll-free access available to callers from the CNMI, which became popular with the advent of pre-paid phone cards. However, since no mobile telephone carriers in the U.S. are present in the CNMI market, cellular calls to the CNMI are not necessarily considered "domestic" or within the definition of "nationwide long distance".

Cost of international calls

FCC's regulation of the CNMI as "domestic" has no legal effect for telephone carriers outside the United States, for whom the CNMI is often not a competitive destination. Therefore, calls from other countries inbound to the CNMI can still be relatively expensive, especially compared to outbound calls from the CNMI since the CNMI has access to most U.S. toll-free numbers.

Dialing

Within the islands, only the seven-digit telephone number is dialed. Calls to and from other NANP regions, such as the United States or Canada, follow standard NANP dialing rules (1+10D). {{Coord, 15, 11, N, 145, 45, E, display=title

Communications in the Northern Mariana Islands Telecommunications-related introductions in 1997