NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

MADISON prefixes in area code 605

NANPA records 8 assigned NXX blocks to rate center MADISON in area code 605, 1.1% of the 745 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 6 holders hold those blocks, the largest being QWEST CORPORATION (2), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - SD (2), BANDWIDTH.COM CLEC, LLC - SD (1). The earliest assignment on record here is 2001-05-17 and the most recent 2023-03-01. 6 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots. The same rate center name also appears in area codes 203, 207, 256, 304 – overlay codes cover the same geography, so a rate center is served by all of them.

8 assigned blocks – 1.1% of 605
6 holders of record
6 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
605-256 Lumen QWEST CORPORATION – no yes
605-270 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - SD – yes yes
605-291 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - SD – yes yes
605-427 Bandwidth BANDWIDTH.COM CLEC, LLC - SD – no yes
605-480 AT&T NEW CINGULAR WIRELESS PCS, LLC - IL – yes yes
605-556 MIDCONTINENT COMMUNICATIONS. - SD 2001-05-17 yes yes
605-621 INTERSTATE TELECOMMUNICATIONS COOPERATIVE, INC. 2023-03-01 yes yes
605-636 Lumen QWEST CORPORATION – yes yes

The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.

Who holds the blocks

HolderBrandBlocksShare here
QWEST CORPORATION Lumen 2 25%
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - SD Verizon 2 25%
BANDWIDTH.COM CLEC, LLC - SD Bandwidth 1 12.5%
NEW CINGULAR WIRELESS PCS, LLC - IL AT&T 1 12.5%
MIDCONTINENT COMMUNICATIONS. - SD – 1 12.5%
INTERSTATE TELECOMMUNICATIONS COOPERATIVE, INC. – 1 12.5%

Same rate center in other codes

Overlay codes cover the same geography, so one rate center is served by all of them.

Frequently asked

Which prefixes belong to MADISON in area code 605?

8 blocks: 256, 270, 291, 427, 480, 556, 621, 636. The table above gives the holder of each.

Which carriers have numbers in MADISON?

QWEST CORPORATION (2 blocks), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - SD (2 blocks), BANDWIDTH.COM CLEC, LLC - SD (1 block), NEW CINGULAR WIRELESS PCS, LLC - IL (1 block), MIDCONTINENT COMMUNICATIONS. - SD (1 block), INTERSTATE TELECOMMUNICATIONS COOPERATIVE, INC. (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is MADISON a city?

It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.

Other rate centers in 605

All 745 prefixes in 605