North American Numbering Plan (NANP)

The NANP is a telephone numbering plan shared by 20 countries and territories, all using the country code +1. It covers the United States, Canada, and numerous Caribbean nations.

+1
Shared Country Code
25 Members

What is the NANP?

The North American Numbering Plan (NANP) is an integrated telephone numbering plan that encompasses 20 countries and territories in North America and the Caribbean. All NANP members share the international country code +1.

The NANP was established in 1947 by AT&T to simplify long-distance calling across North America. It is now administered by the North American Numbering Plan Administration (NANPA), which is responsible for assigning area codes and managing the numbering resources.

Under the NANP, each phone number follows a standardized 10-digit format: a 3-digit area code (also called Numbering Plan Area or NPA) followed by a 7-digit local number (3-digit exchange code + 4-digit subscriber number).

How the NANP Works

Number Format

+1 - NPA - NXX - XXXX
+1
Country Code
NPA
Area Code (3 digits)
NXX
Exchange (3 digits)
XXXX
Subscriber (4 digits)

Key Rules

  • Area codes (NPA) are three digits. The first digit is 2-9 (never 0 or 1). The format is NXX where N=2-9 and X=0-9.
  • Exchange codes (NXX) follow the same rule: the first digit is 2-9.
  • N11 codes (like 911, 411, 311) are reserved for special services and cannot be used as area codes.
  • Toll-free numbers use area codes 800, 888, 877, 866, 855, 844, and 833.

Dialing Within the NANP

Domestic (same area code)

NXX-XXXX

7-digit dialing (being phased out in many areas)

Long distance (different area code)

1-NPA-NXX-XXXX

11-digit dialing with the 1 prefix

Good to know: Calls between NANP countries (e.g., US to Jamaica) are dialed as 1-area code-number, just like a US domestic long-distance call. However, they are still billed as international calls by most carriers.

NANP Countries & Territories

# Country / Territory Dialing Code Type Actions
1 United States +1 Country
2 Canada +1 Country
3 Bahamas +1-242 Country
4 Barbados +1-246 Country
5 Anguilla +1-264 Territory
6 Antigua and Barbuda +1-268 Country
7 British Virgin Islands +1-284 Territory
8 US Virgin Islands +1-340 Territory
9 Cayman Islands +1-345 Territory
10 Bermuda +1-441 Territory
11 Grenada +1-473 Country
12 Turks and Caicos Islands +1-649 Territory
13 Montserrat +1-664 Territory
14 Northern Mariana Islands +1-670 Territory
15 Guam +1-671 Territory
16 American Samoa +1-684 Territory
17 Sint Maarten +1-721 Territory
18 Puerto Rico +1-787/939 Territory
19 Dominican Republic +1-809/829/849 Country
20 Saint Lucia +1-758 Country
21 Dominica +1-767 Country
22 Saint Vincent and the Grenadines +1-784 Country
23 Trinidad and Tobago +1-868 Country
24 Saint Kitts and Nevis +1-869 Country
25 Jamaica +1-876 Country

Frequently Asked Questions

The NANP was created in 1947 when the telephone system was primarily managed by AT&T across North America. At that time, the US, Canada, and several Caribbean nations were all part of the Bell System. Rather than assigning separate country codes, they were unified under +1 with unique area codes distinguishing each country or territory.

Although NANP calls are dialed the same way as US domestic long-distance calls (1 + area code + number), calls to other NANP countries are typically billed as international calls. Check with your carrier for specific rates to Caribbean NANP destinations. Calls between the US and Canada are often included in domestic plans, but Caribbean destinations usually are not.

No. Because all NANP countries share the +1 country code, you do not need to dial the international access code (011). Simply dial 1 + area code + 7-digit number, just like a US long-distance call. For example, to call Jamaica: 1-876-XXX-XXXX.

The area code identifies the country or territory. For example, area codes starting with 876 are Jamaica, 242 is the Bahamas, and 868 is Trinidad and Tobago. US and Canadian area codes cover the remaining area code ranges. You can use our area code directory to look up any area code.

The NANP is administered by the North American Numbering Plan Administration (NANPA), which is currently operated by Somos, Inc. under contract with the Federal Communications Commission (FCC). NANPA is responsible for assigning area codes, managing the numbering plan, and ensuring efficient use of numbering resources.
NANP Quick Facts
  • Country Code +1
  • Established 1947
  • Members 25
  • Number Format 10 digits
  • Administrator NANPA
  • Regulator FCC (US)
Related Pages
How to Dial NANP Numbers

From anywhere in the US or NANP zone:

1 - (area code) - XXX-XXXX

No need to dial 011 or +. Just dial 1 followed by the area code and number, the same way you make a US long-distance call.