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

SAPPINGTON prefixes in area code 557

NANPA records 5 assigned NXX blocks to rate center SAPPINGTON in area code 557, 6.0% of the 84 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 NEW CINGULAR WIRELESS PCS, LLC - IL (2), ONVOY, LLC - MO (2), WIRETAP TELECOM, LLC. (1). The earliest assignment on record here is 2022-09-16 and the most recent 2026-07-08. 5 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 code 314 – overlay codes cover the same geography, so a rate center is served by all of them.

5 assigned blocks – 6% of 557
3 holders of record
5 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
557-217 AT&T NEW CINGULAR WIRELESS PCS, LLC - IL 2023-11-15 yes yes
557-230 AT&T NEW CINGULAR WIRELESS PCS, LLC - IL 2024-12-30 yes yes
557-259 Onvoy ONVOY, LLC - MO 2026-07-08 yes no
557-333 Onvoy ONVOY, LLC - MO 2025-07-15 yes yes
557-999 WIRETAP TELECOM, LLC. 2022-09-16 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
NEW CINGULAR WIRELESS PCS, LLC - IL AT&T 2 40%
ONVOY, LLC - MO Onvoy 2 40%
WIRETAP TELECOM, LLC. – 1 20%

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 SAPPINGTON in area code 557?

5 blocks: 217, 230, 259, 333, 999. The table above gives the holder of each.

Which carriers have numbers in SAPPINGTON?

NEW CINGULAR WIRELESS PCS, LLC - IL (2 blocks), ONVOY, LLC - MO (2 blocks), WIRETAP TELECOM, 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 SAPPINGTON 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 557

All 84 prefixes in 557