North American Numbers Source-cited · ownership disclosed
Area code
475
In service
United States · since 2009

Southwestern Connecticut (overlay)

Area code 475 is an all-services overlay of 203, serving the identical southwestern Connecticut territory. It went into service December 12, 2009.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Southwestern Connecticut (overlay)
Type
geographic
Status
in service
In service since
2009
Projected exhaust
2055 Q4

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 475 is

Same as 203: most of Fairfield County, all of New Haven County, and parts of Litchfield County..

Communities served wholly or partly by 475:

BridgeportNew HavenWaterburyStamfordDanburyNorwalkMeriden

Shares the same geographic footprint as 203.

B · Relationships

How it relates to other codes

The codes 475 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 · 2009 203 Southwestern Connecticut 475 is the overlay of 203, sharing the same geographic area.
What's changing. Overlay of 203 (both codes serve the same area simultaneously); ten-digit dialing required.
C · History

How 475 got here

1999-08
Overlay first proposed by the Connecticut Department of Public Utility Control.
Source: Wikipedia
2009-12-12
Area code 475 placed in service as an overlay of 203.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
304
Prefixes available
496
Thousands-blocks assigned
2,738

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

Compare 475 with another code →
Sources
Wikipedia ↗
Area code 475
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.