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

ALTAMONT prefixes in area code 618

NANPA records 3 assigned NXX blocks to rate center ALTAMONT in area code 618, 0.4% of the 786 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. 3 holders hold those blocks, the largest being CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL (1), BANDWIDTH.COM CLEC, LLC - IL (1), MCC TELEPHONY LLC (1). The earliest assignment on record here is 2005-06-03 and the most recent 2021-06-29. 2 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 435, 518, 620, 838 – overlay codes cover the same geography, so a rate center is served by all of them.

3 assigned blocks – 0.4% of 618
3 holders of record
2 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
618-483 Frontier CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL – no yes
618-738 Bandwidth BANDWIDTH.COM CLEC, LLC - IL 2021-06-29 yes yes
618-881 MCC TELEPHONY LLC 2005-06-03 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
CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL Frontier 1 33.3%
BANDWIDTH.COM CLEC, LLC - IL Bandwidth 1 33.3%
MCC TELEPHONY LLC – 1 33.3%

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 ALTAMONT in area code 618?

3 blocks: 483, 738, 881. The table above gives the holder of each.

Which carriers have numbers in ALTAMONT?

CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL (1 block), BANDWIDTH.COM CLEC, LLC - IL (1 block), MCC TELEPHONY LLC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is ALTAMONT 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 618

All 786 prefixes in 618