---
title: "Illinois Bell Tel phone number prefixes"
url: "https://lookvalid.com/carriers/illinois-bell-tel.md"
canonical_url: "https://lookvalid.com/carriers/illinois-bell-tel"
last_updated: "2026-10-19"
type: "reference"
summary: "Illinois Bell Tel holds 1,909 of the 197,646 phone prefixes in service (<1%), across 2 states and territories and 14 area codes, per NANPA."
related: ["https://lookvalid.com/carriers.md", "https://lookvalid.com/tools/carrier-lookup.md"]
---

# Illinois Bell Tel phone number prefixes

Illinois Bell Tel holds 1,909 of the 197,646 phone prefixes in service (<1%), across 2 states and territories and 14 area codes, per NANPA.

Illinois Bell Tel is one of the largest holders of North American phone number prefixes. NANPA assigned it 1,909 of the 197,646 central office codes in service, <1% of the total.

## Holder type

Landline telephone company. AT&T's consumer service terms name Illinois Bell Telephone Company among the AT&T companies that provide AT&T Phone Service, a wireline home phone service. Source: https://www.att.com/legal/terms.consumerServiceAgreement.html, read 2026-10-19.

## Facts

- Prefixes held: 1,909 of 197,646 in service (<1%)
- States and territories: 2
- Area codes: 14
- Pooled prefixes: 712 of 1,909 (37%)
- Thousands-blocks held in pooled prefixes: 952
- Rate centers: 240
- Registered names: Illinois Bell Tel CO
- Operating company numbers under this name: 1

## Prefixes by state or territory

| State or territory | Prefixes |
| --- | --- |
| IL | 1,908 |
| WI | 1 |

## Prefixes by area code

| Area code | Prefixes |
| --- | --- |
| [847](https://lookvalid.com/area-code/847.md) | 361 |
| [312](https://lookvalid.com/area-code/312.md) | 334 |
| [630](https://lookvalid.com/area-code/630.md) | 258 |
| [773](https://lookvalid.com/area-code/773.md) | 257 |
| [708](https://lookvalid.com/area-code/708.md) | 178 |
| [815](https://lookvalid.com/area-code/815.md) | 157 |
| [217](https://lookvalid.com/area-code/217.md) | 129 |
| [618](https://lookvalid.com/area-code/618.md) | 111 |
| [309](https://lookvalid.com/area-code/309.md) | 83 |
| [224](https://lookvalid.com/area-code/224.md) | 34 |
| [872](https://lookvalid.com/area-code/872.md) | 3 |
| [331](https://lookvalid.com/area-code/331.md) | 2 |
| [262](https://lookvalid.com/area-code/262.md) | 1 |
| [779](https://lookvalid.com/area-code/779.md) | 1 |

## Caveats

The holder is the company NANPA assigned the codes to, under the legal name it registered, which can differ from the brand customers see. Numbers port, so a number in one of these prefixes may now be with another carrier. To see which carrier holds a number's block, use the [carrier lookup](https://lookvalid.com/tools/carrier-lookup.md).

See all holders in the [ranked table](https://lookvalid.com/carriers.md).

Source: NANPA central office code report dated 2026-10-17 and thousands-block report dated 2026-10-17.

## Related

- [Largest phone number holders by prefix](https://lookvalid.com/carriers.md)
- [Free carrier lookup](https://lookvalid.com/tools/carrier-lookup.md)