Phone numbers in the United States (+1)

Dialling and writing numbers in the United States

The trunk prefix is dialled in front of a number inside the country and dropped after the calling code; the international prefix is dialled to call out of it. The lengths and the leading digits below say which numbers the plan accepts and what their first digits tell you about the line type.

Lengths count the national significant number, the digits after the calling code, without the trunk prefix. Every value is read from libphonenumber’s metadata, release 9.0.41, which a lookup runs on.

One number in each of its written forms

The number is fictional: NANPA reserves 555-0100 to 555-0199 for fiction in every area code.

The numbering plan for the United States

Every phone lookup starts from the numbering metadata: it settles whether a number is valid for the United States, how it is written nationally and internationally, and which line type its range belongs to. The example numbers below are libphonenumber’s examples of each line type’s format; one may be in service, so read them for their shape and never dial or text one as a test.

+1 is shared with American Samoa, Anguilla, Antigua & Barbuda, Bahamas, Barbados, Bermuda, British Virgin Islands, Canada, Cayman Islands, Dominica, Dominican Republic, Grenada, Guam, Jamaica, Montserrat, Northern Mariana Islands, Puerto Rico, Sint Maarten, St. Kitts & Nevis, St. Lucia, St. Vincent & Grenadines, Trinidad & Tobago, Turks & Caicos Islands, U.S. Virgin Islands, so the region of a number is settled by its area code, not by the calling code alone.

The regulator table behind a lookup here

NANPA central office code report (synced 2026-10-25, table version 2026-10-24). The table is complete: it lists every assigned block of its plan, so a geographic number outside it is called unassigned. A lookup names the block holder as carrier with carrier_source block_allocation — the original allocation, never who serves the number today.

• 205,199 blocks in the table: 198,695 allocated, 0 unassigned, 6,504 reserved.
• 96.8 % of the blocks are allocated.
• 100.0 % of allocated blocks name a holder.
• 44.9 % of allocated blocks settle the line type on their own (60,397 mobile, 28,739 VoIP).

Measured weekly (last on 2026-10-25) from the table itself. These are shares of the regulator’s own table, not of real traffic, and they say nothing about who serves any one number today.

Who publishes the table, its files and terms, and what the copy installed here holds are on its data source page.

Counts across the North American tables, such as the codes and thousands-blocks assigned in the last 7, 30 and 365 days, are on the phone statistics page, counted from public data only.

Network carriers by numbers allocated

Spaw groups the holders in the NANPA central office code report under network brands. Each carrier’s page counts the numbers its legal entities were allocated, as a share of the regulator’s table: original allocation, not who serves a number today, and not a share of subscribers or traffic.

• AT&T23.5%
• Verizon17.1%
• T-Mobile12.7%
• Inteliquent11.7%
• Lumen6.6%
• Bandwidth4.2%
• Windstream2.9%
• Frontier2.5%
• Comcast1.3%
• Peerless Network1.1%
• Spok1.0%
• Brightspeed1.0%
• Charter0.9%
• Telnyx0.7%
• Commio0.5%
• Consolidated Communications0.4%
• Optimum0.2%
• TPx0.2%
• Ziply Fiber0.2%
• Boost Mobile0.2%
• altafiber0.2%
• Hawaiian Telcom0.1%
• Mediacom0.1%
• GCI0.1%

Every brand in the tables Spaw groups is on the network carriers index.

What a lookup answers for a number here

Every number the plan accepts for the United States comes back with its formats, its line_type and line_type_source, its region and timezones, and the is_fictional and is_disposable flags from the bundled fiction ranges and the synced list of SMS-receiving numbers. Because the NANPA central office code report covers the United States, a lookup also answers carrier from the block holder and block_status for every geographic number, unassigned included.

Several zones. The United States keeps more than one clock, so a lookup answers timezones per number from its area code and exchange where the plan settles it.

Area codes by state

39 states and the District of Columbia have more than one area code and a page of their own: the codes with their overlays and in-service dates, the codes allocated there, the rate centres and the codes assigned in the last twelve months, counted from the NANPA central office code report. The rest have one area code each, listed below with its own page.

• Alabama7 codes
• Arizona5 codes
• Arkansas4 codes
• California41 codes
• Colorado6 codes
• Connecticut4 codes
• District of Columbia2 codes
• Florida23 codes
• Georgia11 codes
• Idaho2 codes
• Illinois17 codes
• Indiana8 codes
• Iowa5 codes
• Kansas4 codes
• Kentucky6 codes
• Louisiana6 codes
• Maryland6 codes
• Massachusetts9 codes
• Michigan13 codes
• Minnesota8 codes
• Mississippi5 codes
• Missouri9 codes
• Nebraska3 codes
• Nevada3 codes
• New Jersey10 codes
• New Mexico2 codes
• New York23 codes
• North Carolina11 codes
• Ohio15 codes
• Oklahoma5 codes
• Oregon4 codes
• Pennsylvania15 codes
• South Carolina6 codes
• Tennessee8 codes
• Texas29 codes
• Utah3 codes
• Virginia10 codes
• Washington State6 codes
• West Virginia2 codes
• Wisconsin8 codes

Area codes in the United States

The United States has 372 area-code pages; each reads the same table for the blocks under its code, their original holders and the line types they settle. Codes put in service in the last two years, those assigned and not yet in service, and those in relief planning are on new and upcoming North American area codes.

code · place its page names · blocks allocated in the NANPA central office code report (original allocation, not who serves a number today)

Run the lookup

The plan’s own example number, answered with every field:

curl https://spaw.co/api/v1/phone \
  -H "Authorization: Bearer sk_live_…" \
  -H "Content-Type: application/json" \
  -d '{"phone": "+1 201-555-0123", "country": "US"}'

Or try one without a key on the free phone number lookup, and read every field in the phone intelligence guide.

Other regions

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• Uzbekistan
• Vatican City
• St. Vincent & Grenadines
• Every region