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
Abiquiu	NM	505	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	36	ABIQUIU, ALBQNM10X2X, ALBQNMMAX4Y +2
Alamogordo	NM	575	QWEST CORPORATION (9636)	664	—	255	ALAMOGORDO MAIN, ALAMOGORDO WEST, ALBQNM10KMD +17
Albuquerque	NM	505	QWEST CORPORATION (9636)	664	—	2,511	ALBQ ACADEMY, ALBQ CORRALES, ALBQ EAST +58
Alto	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	18	ALBQNMMAX2Y, ALBQNMMAX4Y, ALBQNMMAXPY +4
Angel Fire	NM	575	QWEST CORPORATION (9636)	664	—	38	ALBQNM10KMD, ALBQNM10X3X, ALBQNMMAX4Y +7
Animas	NM	575	VALLEY TEL COOP INC (2176)	664	—	1	ANIMAS
Antelope Ridge	NM	575	LEACO RURAL TEL. COOP., INC. (2264)	664	—	1	TATUM
Anthony	NM	575	QWEST CORPORATION (9636)	664	—	72	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X3X +15
Anton Chico	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	CLOVIS
Arch	NM	575	ROOSEVELT COUNTY RURAL TEL. COOP., INC. (2272)	664	—	1	ARCH
Artesia	NM	575	QWEST CORPORATION (9636)	664	—	110	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X3X +15
Aztec	NM	505	QWEST CORPORATION (9636)	664	—	191	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X3X +14
Bayard	NM	575	QWEST CORPORATION (9636)	664	—	43	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X3X +10
Bellview	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	BELLVIEW
Bingham	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	CLOVIS
Canjilon	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	14	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXPY +1
Cannon AFB	NM	575	QWEST CORPORATION (9636)	664	—	94	ALBQNM10KMD, ALBQNM10X2X, ALBQNMMAX2Y +10
Capitan	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	19	ALBQNMMAX2Y, ALBQNMMAX4Y, ALBQNMMAXQX +4
Carlsbad	NM	575	VALOR TELECOM TX,LP-NM #1 DBA WINDSTREAM COMM SW (1164)	664	—	121	ALBQNM10LMD, ALBQNM10X3X, ALBQNMMAX2Y +13
Carlsbad Caverns	NM	575	VALOR TELECOM TX,LP-NM #1 DBA WINDSTREAM COMM SW (1164)	664	—	25	ALBQNM10X3X, ALBQNMMAX2Y, ALBQNMMAX4Y +4
Carrizozo	NM	575	TULAROSA BASIN TELEPHONE CO., INC. (2265)	664	—	3	TLRSNMXC1MD, TULAROSA
Causey	NM	575	ROOSEVELT COUNTY RURAL TEL. COOP., INC. (2272)	664	—	1	ARCH
Chama	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	30	ALBQNM10QMD, ALBQNMMAX4Y, ALBQNMMAX7Y +4
Chaparral	NM	575	QWEST CORPORATION (9636)	664	—	51	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X3X +10
Chimayo	NM	505	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	14	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXPY +1
Cimarron	NM	575	QWEST CORPORATION (9636)	664	—	21	ALBQNM10KMD, ALBQNMMAX2Y, ALBQNMMAX4Y +6
Clayton	NM	575	E.N.M.R. TEL COOP (2262)	664	—	6	ALBQNMMAXLX, ALBQNMMAXQX, ALBQNMMAXSY +1
Cliff	NM	575	WESTERN NEW MEXICO TEL. CO., INC. (2268)	664	—	1	CLIFF
Cloudcroft	NM	575	TULAROSA BASIN TELEPHONE CO., INC. (2265)	664	—	5	ARTSNMMA0MD, TLRSNMXC1MD, TULAROSA
Clovis	NM	575	QWEST CORPORATION (9636)	664	—	140	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X6X +14
Columbus	NM	575	VALLEY TEL COOP INC (2176)	664	—	1	ANIMAS
Conchas Dam	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	CONCHAS DAM
Corona	NM	575	E.N.M.R. TEL COOP (2262)	664	—	4	ALBQNM10X2X, ALBQNM10X3X, CORONA
Cottonwood	NM	575	PENASCO VALLEY TEL. COOP., INC. (2270)	664	—	2	COTTONWOOD
Crown Point	NM	505	NAVAJO COMM CO INC NM DBA NAVAJO COMM CO NM (4450)	664	—	11	ALBQNMMAXLX, ALBQNMMAXQX, ALBQNMMAXSY +1
Cuba	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	14	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAX7Y +3
Datil	NM	575	WESTERN NEW MEXICO TEL. CO., INC. (2268)	664	—	10	ALBQNMMAXQX, DATIL
Deming	NM	575	QWEST CORPORATION (9636)	664	—	91	ALBQNM10KMD, ALBQNM10LMD, ALBQNM10X3X +14
Des Moines	NM	575	BACA VALLEY TEL. CO., INC. (2259)	664	—	1	DES MOINES
Dexter	NM	575	LEACO RURAL TEL. COOP., INC. (2264)	664	—	1	TATUM
Dixon	NM	505	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	13	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXPY +1
Dora	NM	575	ROOSEVELT COUNTY RURAL TEL. COOP., INC. (2272)	664	—	1	ARCH
Dulce	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	20	ALBQNMMAX4Y, ALBQNMMAX7Y, ALBQNMMAXPY +2
East Hobbs	TX	432	VALOR TELECOMM TX, LP-TX #1 DBA WINDSTREAM COMM SW (1163)	664	—	19	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXPY +2
El Rito	NM	575	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	10	ALBQNMMAX4Y, ALBQNMMAXPY, EL RITO
El Valle	NM	575	E.N.M.R. TEL COOP (2262)	664	—	1	EL VALLE
Elida	NM	575	ROOSEVELT COUNTY RURAL TEL. COOP., INC. (2272)	664	—	1	ARCH
Espanola	NM	505	VALOR TELECOM TX,LP-NM #2 DBA WINDSTREAM COMM SW (1193)	664	—	101	ALBQNM10LMD, ALBQNM10QMD, ALBQNM10X2X +10
Eunice	NM	575	VALOR TELECOM TX,LP-NM #1 DBA WINDSTREAM COMM SW (1164)	664	—	31	ALBQNM10X2X, ALBQNM10X3X, ALBQNMMAX2Y +7
Eunice West	TX	432	VALOR TELECOMM TX, LD-TX #2 DBA WINDSTREAM COMM SW (1181)	664	—	14	ALBQNM10X3X, ALBQNMMAX4Y, ALBQNMMAXPY +3

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.