Suffolk County (overlay)

All-service overlay of area code 631, serving Suffolk County on Long Island. First overlay in NY outside NYC.

The essentials Numbering data · NumberResearch · as of 2026-09-18

Place

Type

geographic

Status

in service

In service since

2016

Projected exhaust

2079 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 934 is

Suffolk County, Long Island, New York.

Communities served wholly or partly by 934:

BabylonHuntingtonIslipSmithtownBrookhavenRiverhead

Shares 631's Suffolk County footprint.

B · Relationships

How it relates to other codes

The codes 934 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 · 2016 631 Suffolk County Overlays 631 as it neared central-office-code depletion.

What's changing. Active overlay of 631 across Suffolk County; ten-digit dialing required.

C · History

How 934 got here

2016-07-16

Assigned to overlay 631; ten-digit dialing required (first NY overlay outside NYC). Note: source shows an internally inconsistent June/July ordering — flagged.

Source: Wikipedia 631/934

D · Capacity

How full it is

Prefixes assigned

147

Prefixes available

653

Thousands-blocks assigned

1,136

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

Compare 934 with another code →

Sources

Wikipedia (secondary) ↗

Area codes 631 and 934

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.