North American Numbers Source-cited · ownership disclosed
Area code
224
In service
United States · since 2002

North/Northwest Chicago Suburbs (overlay of 847)

Area code 224 is an all-services overlay of 847, sharing the exact same north/northwest suburban geography. Its first code was activated in December 2001 and the overlay took effect January 5, 2002.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
North/Northwest Chicago Suburbs (overlay of 847)
Type
geographic
Status
in service
In service since
2002
Projected exhaust
2033 Q3

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 224 is

Same as 847 - most of Lake County, northern Cook County, northern Kane County, and a small part of McHenry County.

Communities served wholly or partly by 224:

EvanstonSchaumburgSkokieWaukeganElginArlington HeightsGlenviewHighland ParkPalatine

Same footprint as 847 (150+ communities); numbers are assigned across the whole 847 territory, not a sub-region.

B · Relationships

How it relates to other codes

The codes 224 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Overlay · 2002 847 North/Northwest Chicago Suburbs 224 overlays 847 over identical geography; effective Jan 5, 2002.
What's changing. Overlay of 847 (not a split); both codes cover identical territory. Ten-digit dialing required.
C · History

How 224 got here

1998
NANPA assigned 224 as the future overlay code for 847.
Source: Illinois Commerce Commission chronology
2001-12-13
First NXX code in the 224 overlay activated.
Source: Illinois Commerce Commission chronology
2002-01-05
224 overlay of 847 took effect; mandatory ten-digit dialing.
Source: Wikipedia - Area codes 847 and 224
D · Capacity

How full it is

Prefixes assigned
609
Prefixes available
191
Thousands-blocks assigned
5,420

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 224 with another code →
Sources
Wikipedia ↗
Area codes 847 and 224
Illinois Commerce Commission ↗
Chronological History of Area Code Relief in Illinois
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.