621 Area CodeHouston, TX
Area code 621 covers Houston and nearby communities in Texas, in the Central Time (CT) zone, home to about 6,400,711 people across 101 cities. It was added in 2025 as an overlay of 346, so the same region uses several codes and every local call needs all ten digits.
Overview
- Major City
- Houston
- State
- Texas (TX)
- Timezone
- Central Time (CT)
- Current Time
- –:––
- Overlay
- Yes – shares area with 281, 346, 713, 832
Overview of the 621 Area Code
What is the 621 area code?
The 621 area code serves Houston, Texas, alongside other established area codes. When you see a 621 number, it indicates a local number within this geographic area.
Why was area code 621 created?
Area code 621 went into service on January 23, 2025, as an overlay of 346. An overlay adds a second code to the same territory instead of splitting it: existing 346 numbers kept their digits, new lines began receiving 621 numbers, and local calls in the region require all ten digits. The same territory also carries 281, 713, and 832.
Geographic Coverage of the 621 Area Code
The 621 area code serves Houston and surrounding areas in Texas. It operates within the Central Time (CT) time zone. It complements the coverage of area codes 281, 346, 713, and 832. This area code covers several key cities, including:
- Houston
- Pasadena
- Pearland
- League City
- Sugar Land
- The Woodlands
Got a call from a 621 number? It came from Houston, TX. Since 621 overlays with 281, 346, 713, and 832, every local call in the region needs all ten digits to land on the right line. Of the listed cities' population, Houston accounts for about 56.9%; the rest is split across 100 smaller cities.
Houston Area Codes Overview
Houston is served by multiple area codes, reflecting its telecommunications needs. The 621 area code operates alongside 281, 346, 713, 832. Here are the area codes serving this region:
The introduction of the 621 area code helped prevent number exhaustion, ensuring a continuous supply of phone numbers across the geographic area.
What cities does area code 621 cover?
| City | State | Population | Population in 621 | % of listed-city population | % of City |
|---|---|---|---|---|---|
| Houston | TX | 2,390,125 | 2,390,125 | 56.9% | 100.0% |
| Pasadena | TX | 149,617 | 149,617 | 3.6% | 100.0% |
| Pearland | TX | 129,620 | 129,620 | 3.1% | 100.0% |
| League City | TX | 118,456 | 118,456 | 2.8% | 100.0% |
| Sugar Land | TX | 109,851 | 109,851 | 2.6% | 100.0% |
| The Woodlands | TX | 93,847 | 71,474 | 2.2% | 76.2% |
| Baytown | TX | 86,004 | 86,004 | 2.1% | 100.0% |
| Missouri City | TX | 78,582 | 78,582 | 1.9% | 100.0% |
| Atascocita | TX | 65,844 | 65,844 | 1.6% | 100.0% |
| Texas City | TX | 57,875 | 0 | 1.4% | 0.0% |
| Fulshear | TX | 54,629 | 54,629 | 1.3% | 100.0% |
| Spring | TX | 54,298 | 54,298 | 1.3% | 100.0% |
| Rosenberg | TX | 42,571 | 42,571 | 1.0% | 100.0% |
| Friendswood | TX | 41,291 | 41,291 | 1.0% | 100.0% |
| Channelview | TX | 38,289 | 38,289 | 0.9% | 100.0% |
| La Porte | TX | 38,046 | 38,046 | 0.9% | 100.0% |
| Mission Bend | TX | 36,501 | 36,501 | 0.9% | 100.0% |
| Deer Park | TX | 34,495 | 34,495 | 0.8% | 100.0% |
| Alvin | TX | 29,869 | 29,869 | 0.7% | 100.0% |
| Katy | TX | 27,741 | 27,741 | 0.7% | 100.0% |
| Cloverleaf | TX | 22,942 | 22,942 | 0.5% | 100.0% |
| Dickinson | TX | 21,941 | 21,941 | 0.5% | 100.0% |
| Manvel | TX | 19,309 | 19,309 | 0.5% | 100.0% |
| Fresno | TX | 19,069 | 19,069 | 0.5% | 100.0% |
| Cinco Ranch | TX | 18,274 | 18,274 | 0.4% | 100.0% |
| Stafford | TX | 17,555 | 17,555 | 0.4% | 100.0% |
| Bellaire | TX | 17,439 | 17,439 | 0.4% | 100.0% |
| Iowa Colony | TX | 17,240 | 17,240 | 0.4% | 100.0% |
| Humble | TX | 16,561 | 16,561 | 0.4% | 100.0% |
| South Houston | TX | 16,146 | 16,146 | 0.4% | 100.0% |
| Pecan Grove | TX | 15,963 | 15,963 | 0.4% | 100.0% |
| Aldine | TX | 15,869 | 15,869 | 0.4% | 100.0% |
| New Territory | TX | 15,186 | 15,186 | 0.4% | 100.0% |
| Tomball | TX | 15,152 | 15,152 | 0.4% | 100.0% |
| West University Place | TX | 15,149 | 15,149 | 0.4% | 100.0% |
| Seabrook | TX | 13,976 | 13,976 | 0.3% | 100.0% |
| Sienna Plantation | TX | 13,721 | 13,721 | 0.3% | 100.0% |
| Richmond | TX | 13,305 | 13,305 | 0.3% | 100.0% |
| Webster | TX | 12,548 | 12,548 | 0.3% | 100.0% |
| Four Corners | TX | 12,382 | 12,382 | 0.3% | 100.0% |
| Greatwood | TX | 11,538 | 11,538 | 0.3% | 100.0% |
| Galena Park | TX | 10,438 | 10,438 | 0.3% | 100.0% |
| Mont Belvieu | TX | 10,229 | 10,229 | 0.2% | 100.0% |
| Cleveland | TX | 9,757 | 9,757 | 0.2% | 100.0% |
| Jacinto City | TX | 9,431 | 9,431 | 0.2% | 100.0% |
| Bacliff | TX | 8,619 | 8,619 | 0.2% | 100.0% |
| Jersey Village | TX | 7,791 | 7,791 | 0.2% | 100.0% |
| Highlands | TX | 7,522 | 7,522 | 0.2% | 100.0% |
| Magnolia | TX | 6,506 | 6,506 | 0.2% | 100.0% |
| Brookshire | TX | 5,782 | 5,782 | 0.1% | 100.0% |
| Nassau Bay | TX | 5,229 | 5,229 | 0.1% | 100.0% |
| San Leon | TX | 4,970 | 4,970 | 0.1% | 100.0% |
| Meadows Place | TX | 4,630 | 4,630 | 0.1% | 100.0% |
| Weston Lakes | TX | 4,514 | 4,514 | 0.1% | 100.0% |
| Hunters Creek Village | TX | 4,482 | 4,482 | 0.1% | 100.0% |
| Spring Valley Village | TX | 4,394 | 4,394 | 0.1% | 100.0% |
| Bunker Hill Village | TX | 3,889 | 3,889 | 0.1% | 100.0% |
| Shenandoah | TX | 3,839 | 3,839 | 0.1% | 100.0% |
| Taylor Lake Village | TX | 3,792 | 3,792 | 0.1% | 100.0% |
| Beach City | TX | 3,456 | 3,456 | 0.1% | 100.0% |
| Barrett | TX | 3,199 | 3,199 | 0.1% | 100.0% |
| Piney Point Village | TX | 3,143 | 3,143 | 0.1% | 100.0% |
| Oak Ridge North | TX | 3,003 | 3,003 | 0.1% | 100.0% |
| El Lago | TX | 2,990 | 2,990 | 0.1% | 100.0% |
| Kemah | TX | 2,853 | 2,853 | 0.1% | 100.0% |
| Fifth Street | TX | 2,486 | 2,486 | 0.1% | 100.0% |
| Arcola | TX | 2,453 | 2,453 | 0.1% | 100.0% |
| Hedwig Village | TX | 2,386 | 2,386 | 0.1% | 100.0% |
| Roman Forest | TX | 2,367 | 2,367 | 0.1% | 100.0% |
| Crosby | TX | 2,299 | 2,299 | 0.1% | 100.0% |
| Pinehurst | TX | 2,226 | 2,226 | 0.1% | 100.0% |
| Splendora | TX | 2,063 | 2,063 | 0.1% | 100.0% |
| Anahuac | TX | 2,023 | 0 | 0.1% | 0.0% |
| Sheldon | TX | 1,990 | 1,990 | 0.0% | 100.0% |
| Patton Village | TX | 1,980 | 1,980 | 0.0% | 100.0% |
| Southside Place | TX | 1,908 | 1,908 | 0.0% | 100.0% |
| Porter Heights | TX | 1,653 | 1,653 | 0.0% | 100.0% |
| Plum Grove | TX | 1,639 | 1,639 | 0.0% | 100.0% |
| Brookside Village | TX | 1,613 | 1,613 | 0.0% | 100.0% |
| Woodbranch | TX | 1,587 | 1,587 | 0.0% | 100.0% |
| Shoreacres | TX | 1,540 | 1,540 | 0.0% | 100.0% |
| Old River-Winfree | TX | 1,383 | 1,383 | 0.0% | 100.0% |
| Clear Lake Shores | TX | 1,294 | 1,294 | 0.0% | 100.0% |
| Pleak | TX | 1,182 | 1,182 | 0.0% | 100.0% |
| Rosharon | TX | 1,152 | 1,152 | 0.0% | 100.0% |
| Fairchilds | TX | 1,039 | 0 | 0.0% | 0.0% |
| Cumings | TX | 981 | 981 | 0.0% | 100.0% |
| Hilshire Village | TX | 837 | 837 | 0.0% | 100.0% |
| Beasley | TX | 805 | 0 | 0.0% | 0.0% |
| Big Thicket Lake Estates | TX | 742 | 0 | 0.0% | 0.0% |
| Hillcrest | TX | 730 | 730 | 0.0% | 100.0% |
| Cove | TX | 682 | 682 | 0.0% | 100.0% |
| Simonton | TX | 662 | 662 | 0.0% | 100.0% |
| Pattison | TX | 628 | 628 | 0.0% | 100.0% |
| Stagecoach | TX | 603 | 603 | 0.0% | 100.0% |
| Liverpool | TX | 551 | 551 | 0.0% | 100.0% |
| North Cleveland | TX | 288 | 288 | 0.0% | 100.0% |
| Morgan's Point | TX | 273 | 273 | 0.0% | 100.0% |
| Bonney | TX | 202 | 202 | 0.0% | 100.0% |
| Thompsons | TX | 184 | 184 | 0.0% | 100.0% |
| Dayton Lakes | TX | 57 | 0 | 0.0% | 0.0% |
City population is shown in full. The share of each city inside 621 is measured from Census tract centroids, not estimated from a rate-center match – so a city split between two codes appears on both, at the fraction each one actually holds. The “% of listed-city population” column uses the full populations of the cities listed here.
What counties does area code 621 cover?
6,400,711 residents across 9 counties, counted inside the 621 boundary — a county split between codes contributes only its part.
| County | State | Population in 621 | % of area-code footprint | % of County |
|---|---|---|---|---|
| Harris County | TX | 4,715,685 | 74% | 100% |
| Fort Bend County | TX | 804,574 | 13% | 98% |
| Montgomery County | TX | 345,035 | 5% | 56% |
| Brazoria County | TX | 244,089 | 4% | 66% |
| Galveston County | TX | 190,638 | 3% | 54% |
| Liberty County | TX | 38,207 | 1% | 42% |
| Chambers County | TX | 33,525 | 1% | 72% |
| Waller County | TX | 20,984 | 0% | 37% |
| San Jacinto County | TX | 7,974 | 0% | 29% |
Sources: City populations – U.S. Census Bureau PEP, Vintage 2024 (SUB-IP-EST2024-POP). State populations – the same program, Vintage 2025 (CO-EST2025-ALLDATA). Area-code footprint and county populations – 2020 Census Centers of Population, mapped against NANP area code boundaries. The share of each city inside a code is measured the same way, against Census place boundaries from the Census Bureau's TIGERweb service. Area code assignments – NANPA CO Code data. See our data methodology.
Has area code 621 been reported for unwanted calls?
Yes – 5 unwanted-call complaints were reported to the FTC for numbers showing a 621 area code (Jun 8 – Jul 21, 2026).
- 100% robocalls
- ↓ 33% vs prior period
Most-reported subjects
- Reducing your debt (credit cards, mortgage, student loans)80%4
- Medical & prescriptions20%1
Caller ID is easily spoofed, so these figures reflect the number shown on caller ID, not the caller's true location – an area code alone never identifies a caller. The FTC does not verify the facts in these complaints. Source: FTC Do Not Call (DNC) Reported Calls Data, retrieved 2026-08-17.
Frequently Asked Questions about the 621 Area Code
Who called me from a 621 number?
A 621 number is assigned to Houston, Texas, so a call may come from there. But caller ID is easy to fake, and scammers often spoof a local 621 code to look nearby, so a 621 number doesn't prove the caller is local. Recently, 5 unwanted-call complaints were reported to the FTC for numbers showing the 621 code (100% flagged as robocalls). If you don't recognize the number, let it go to voicemail; a real caller will leave a message.
Is 621 a scam area code?
No area code is a scam on its own. 621 is a normal, officially assigned code for Houston, Texas. Spam callers spoof local codes to raise the odds you answer, so 621 on your caller ID says nothing about who is really calling. Recently, 5 unwanted-call complaints were reported to the FTC for numbers showing the 621 code (100% flagged as robocalls). Judge the call itself, not the area code.
Why do I keep getting calls from the 621 area code?
Repeated calls from different 621 numbers are usually spoofing: a robocaller rotates through 621 numbers so each call looks local and slips past simple blocks. Recently, 5 unwanted-call complaints were reported to the FTC for numbers showing the 621 code (100% flagged as robocalls). Blocking one number rarely helps; voicemail screening, your carrier spam filter, and the Do Not Call Registry work better.
Should I answer an unknown 621 number?
If you aren't expecting a 621 call, let it ring to voicemail. Legitimate callers leave a message, most robocallers hang up when no one picks up, and answering can mark your number as active and bring more calls.
How do I block calls from the 621 area code?
Block a single 621 number from your recent-calls list (iPhone: tap the number, then Block this Caller; Android: tap the number, then Block or report spam). To cut the volume, turn on Silence Unknown Callers on iPhone or spam protection on Android, enable spam filtering from your carrier, and register at DoNotCall.gov. Blocking the entire 621 code also stops legitimate local calls, so use it only as a last resort.
Where is area code 621?
Area code 621 covers Houston and the surrounding area in Texas, spanning 101 cities with about 6,400,711 residents. It shares its area with overlay codes 281, 346, 713, 832.
When did area code 621 go into service?
Area code 621 went into service on January 23, 2025. It was added as an overlay of 346, so 621 numbers serve the same area that 346 already covered.
Is 621 a real area code?
Yes. 621 is an active code in the North American Numbering Plan, assigned by NANPA and in service for Houston, Texas. A real code can still show up on spoofed spam calls, so treat unknown 621 calls with normal caution.
What timezone is the 621 area code in?
The 621 area code is in the Central Time (CT). Because a number can be kept when someone moves or switches to VoIP, a specific 621 caller may not be in that zone.
How do I call a 621 number from abroad?
From outside the US, dial your country's exit code, then 1 (the US country code), then 621 and the seven-digit number. From a mobile phone you can usually just enter +1 621 followed by the number and let the phone add the exit code for you.