Rate Centre Lookup

21,763 rate centres across the United States and Canada. A rate centre is the telephone exchange area a number is homed to — the thing that decides which area codes can serve an address, and whether a call between two points is local.

Rate centre	Region	Area codes	Incumbent	LATA	LIR	Blocks	Switches
Farmington	NM	505	QWEST CORPORATION (9636)	664	—	577	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X2X +19
Fence Lake	NM	505	CENTURYTEL SOUTHWEST INC-NM DBA CENTURYLINK - NM (2274)	664	—	24	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXKY +3
Floyd	NM	575	ROOSEVELT COUNTY RURAL TEL. COOP., INC. (2272)	664	—	1	ARCH
Fort Sumner	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	FORT SUMNER
Gallina	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	14	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXLX +2
Gallup	NM	505	QWEST CORPORATION (9636)	664	—	311	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10QMD +18
Glenwood	NM	575	WESTERN NEW MEXICO TEL. CO., INC. (2268)	664	—	1	GLENWOOD
Grady	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	CLOVIS
Grants	NM	505	QWEST CORPORATION (9636)	664	—	146	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10MMD +14
Hagerman	NM	575	LEACO RURAL TEL. COOP., INC. (2264)	664	—	1	TATUM
Hatch	NM	575	QWEST CORPORATION (9636)	664	—	39	ALBQNM10KMD, ALBQNM10X3X, ALBQNMMAX2Y +8
Hillsboro	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	17	ALBQNMMAX4Y, ALBQNMMAXLX, ALBQNMMAXPY +1
Hobbs	NM	575	VALOR TELECOM TX,LP-NM #1 DBA WINDSTREAM COMM SW (1164)	664	—	154	ALBQNM10LMD, ALBQNMMAX2Y, ALBQNMMAX4Y +13
Hondo	NM	575	PENASCO VALLEY TEL. COOP., INC. (2270)	664	—	1	HONDO
Hope	NM	575	PENASCO VALLEY TEL. COOP., INC. (2270)	664	—	1	HOPE
House	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	HOUSE
Jal	NM	575	VALOR TELECOM TX,LP-NM #1 DBA WINDSTREAM COMM SW (1164)	664	—	25	ALBQNMMAX2Y, ALBQNMMAX4Y, ALBQNMMAXLX +2
Jemez Springs	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	15	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXPY +2
La Mesa	NM	575	QWEST CORPORATION (9636)	664	—	37	ALBQNM10KMD, ALBQNM10X3X, ALBQNMMAX2Y +9
Lakewood	NM	575	PENASCO VALLEY TEL. COOP., INC. (2270)	664	—	1	LAKEWOOD
Las Cruces	NM	575	QWEST CORPORATION (9636)	664	—	459	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10QMD +26
Las Vegas	NM	505	QWEST CORPORATION (9636)	664	—	113	ALBQNM10KMD, ALBQNMMAX2Y, ALBQNMMAX4Y +13
Lindrith	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	21	ALBQNMMAX4Y, ALBQNMMAXLX, ALBQNMMAXPY +1
Loco Hills	NM	575	PENASCO VALLEY TEL. COOP., INC. (2270)	664	—	1	LOCO HILLS
Logan	NM	575	E.N.M.R. TEL COOP (2262)	664	—	7	ALBQNM10X2X, ALBQNMMAXLX, ALBQNMMAXSY +2
Lordsburg	NM	575	WESTERN NEW MEXICO TEL. CO., INC. (2268)	664	—	7	ALBRNMFE5MD, LORDSBURG
Los Alamos	NM	505	QWEST CORPORATION (9636)	664	—	126	ALBQNM10KMD, ALBQNM10LMD, ALBQNMMAX2Y +11
Loving	NM	575	VALOR TELECOM TX,LP-NM #1 DBA WINDSTREAM COMM SW (1164)	664	—	21	ALBQNMMAX2Y, ALBQNMMAX4Y, ALBQNMMAXLX +4
Lovington	NM	575	VALOR TELECOM TX,LP-NM #1 DBA WINDSTREAM COMM SW (1164)	664	—	34	ALBQNM10X2X, ALBQNM10X3X, ALBQNMMAX2Y +9
Luna	NM	575	WESTERN NEW MEXICO TEL. CO., INC. (2268)	664	—	1	LUNA
Lybrook	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	19	ALBQNMMAX4Y, ALBQNMMAXLX, ALBQNMMAXPY +1
Magdalena	NM	575	WESTERN NEW MEXICO TEL. CO., INC. (2268)	664	—	6	ALBQNM10X2X, ALBQNM10X3X, ALBQNMMAXQX +1
Maljamar	NM	575	LEACO RURAL TEL. COOP., INC. (2264)	664	—	1	TATUM
Maxwell	NM	575	BACA VALLEY TEL. CO., INC. (2259)	664	—	1	DES MOINES
Mayhill	NM	575	PENASCO VALLEY TEL. COOP., INC. (2270)	664	—	1	MAYHILL
Melrose	NM	575	ROOSEVELT COUNTY RURAL TEL. COOP., INC. (2272)	664	—	1	ARCH
Mescalero	NM	575	MESCALERO APACHE TELECOM, INC. - NM (1231)	664	—	1	MESCALERO
Milnesand	NM	575	ROOSEVELT COUNTY RURAL TEL. COOP., INC. (2272)	664	—	1	ARCH
Mimbres	NM	575	WESTERN NEW MEXICO TEL. CO., INC. (2268)	664	—	1	MIMBRES
Mora	NM	575	LA JICARITA RURAL TEL. COOP., INC. (2263)	664	—	5	ALBQNM10QMD, ALBQNMMAXQX, MORA
Mosquero	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	MOSQUERO
Nara Visa	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	NARA VISA
Naschitti	NM	505	NAVAJO COMM CO INC NM DBA NAVAJO COMM CO NM (4450)	664	—	10	ALBQNM10X3X, ALBQNMMAXLX, ALBQNMMAXSY +1
Navajo	NM	505	NAVAJO COMM CO INC NM DBA NAVAJO COMM CO NM (4450)	664	—	10	ALBQNM10QMD, ALBQNMMAXLX, ALBQNMMAXSY +1
Newcomb	NM	505	NAVAJO COMM CO INC NM DBA NAVAJO COMM CO NM (4450)	664	—	9	ALBQNMMAXLX, ALBQNMMAXSY, NEWCOMB
Ojo Caliente	NM	505	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	29	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXPY +1
Pecos	NM	505	CENTURYTEL SOUTHWEST INC-NM DBA CENTURYLINK - NM (2274)	664	—	20	ALBQNM10X2X, ALBQNMMAX4Y, ALBQNMMAXKY +2
Penasco	NM	575	QWEST CORPORATION (9636)	664	—	31	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X3X +7
Pine Hill	NM	505	CENTURYTEL SOUTHWEST INC-NM DBA CENTURYLINK - NM (2274)	664	—	20	ALBQNM10X2X, ALBQNMMAX4Y, ALBQNMMAXKY +2
Playas	NM	575	VALLEY TEL COOP INC (2176)	664	—	1	ANIMAS

Searching for a place, not a rate centre?

Many places are localities inside a larger rate centre and hold no numbers of their own, so they are not listed above — Clinton, Maryland is part of Washington Zone 16. The Area Codes tab resolves a place name through to whichever rate centre actually serves it.

What These Terms Mean

The fields shown on the area code, rate centre and LATA pages, in plain language.

Rate centre — The exchange area a number belongs to: The telephone exchange area a block of numbers is homed to, and what decides whether a call between two points is local. It is not a city: many places are localities inside a larger rate centre and have no numbers of their own. Clinton, Maryland is part of the Washington Zone 16 rate centre, so its numbers are 227, 240 and 301.
NPA-NXX — Area code and prefix: The first six digits of a North American number. NPA is the three-digit area code, NXX the three-digit prefix — so 416-200 is NPA 416, NXX 200. Knowing the NPA-NXX identifies the exchange a number was issued from.
Thousands-block — A prefix split into ten pieces: A prefix holds 10,000 numbers, which is more than most carriers need, so prefixes are pooled: split into ten blocks of a thousand and handed to different carriers. The block digit is the fourth digit of the number, and A means the whole prefix went to one carrier. This is why 512 has 783 prefixes but 6,011 rows — 512-555-1xxx and 512-555-2xxx can belong to different companies.
OCN — The carrier holding the block: Operating Company Number — a four-character code identifying the carrier of record for a block. Two carriers can share a brand name and still have different OCNs, which is why the tables show the number alongside the name.
ILEC — The incumbent operator for the area: Incumbent Local Exchange Carrier — the established local operator for a rate centre, usually the former Bell company. It differs from the OCN whenever a block belongs to a competitor: a Toronto block can be held by Bell Cellular while the incumbent for the rate centre is Bell Ontario.
LATA — Where a call stops being local: Local Access and Transport Area — the region a call is routed within before it becomes long-haul. The boundaries date from the 1984 Bell System breakup and still shape how calls are routed and rated. A LATA is three digits, though some rate centres are published with a two-digit sub-code appended, shown here as 460.17. Browse every LATA.
LIR — The Canadian equivalent, roughly: Local Interconnection Region — how Canadian carriers divide territory for exchanging traffic. It only applies in Canada, so this field is blank on every US record by definition rather than by omission.
Switch / CLLI — The equipment serving the block: The telephone switch a block is routed through, named by its CLLI code — an eleven-character identifier where the first characters encode the place, as in TOROON01DS0 for Toronto. A switch typed POI is a point of interconnection, where carriers hand traffic to each other rather than serve subscribers directly.
Overlay and split — The two ways to add an area code: A split divides a region and gives part of it a new code, so existing numbers change. An overlay adds a code on top of the same territory, so nobody has to change a number — but everyone has to dial ten digits, since two numbers in the same place can now differ only by area code. 786 overlaid 305 in 1998; 941 split from 813 in 1995.

One limitation worth knowing. All of this describes the block a number was issued from. Number portability means a number can be carried to another carrier while keeping its digits, so the carrier shown is the carrier of record for the block, not necessarily whoever serves that specific line today. Nothing in this data can tell you which — only a live portability lookup can.