North American Numbers Source-cited · ownership disclosed
Area code
621
In service
United States · since 2025

Houston (overlay)

The newest (fifth) Houston-area overlay, in service January 23, 2025, sharing the same territory as 713/281/832/346. Added to relieve number exhaustion.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Houston (overlay)
Type
geographic
Status
in service
In service since
2025
Projected exhaust
2039 Q2

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 621 is

Greater Houston metropolitan area, Texas (same footprint as 281/346/713/832).

Communities served wholly or partly by 621:

HoustonBaytownLeague CityMissouri CityPasadenaPearlandSugar LandThe Woodlands

Representative list from the PUC press release; as a distributed overlay it has no distinct geography.

B · Relationships

How it relates to other codes

The codes 621 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 · 2025 713 Houston 621 added as an all-services distributed overlay of the 281/346/713/832 complex.
Overlay · 2025 281 Houston Co-overlay of the same region.
Overlay · 2025 832 Houston (overlay) Co-overlay of the same region.
Overlay · 2025 346 Houston (overlay) Co-overlay of the same region.
What's changing. Newest (fifth) member of the 713/281/832/346/621 all-services distributed overlay. Mandatory 10-digit dialing. Confirmed by two primary sources (NANPA PL-623 and PUC press release).
C · History

How 621 got here

2024-10-23
Test-routing window opened (through Feb 23, 2025; test number 621-621-1621).
Source: NANPA Planning Letter PL-623
2025-01-23
In-service date: numbers beginning with 621 could be assigned in the Houston complex.
Source: NANPA Planning Letter PL-623 / PUC of Texas press release
D · Capacity

How full it is

Prefixes assigned
14
Prefixes available
786

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

Compare 621 with another code →
Sources
NANPA ↗
Planning Letter PL-623 (NPA 621)
PUC of Texas / NANPA ↗
Press release: New 621 Houston Area Code (Jan 15, 2025)
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.