Area code
512
512 is a United States area code. Under the North American Numbering Plan it belongs to Texas, which has 29 area codes in total.
Validate a number in 512
Paste a full number and the tool checks it against the numbering plan. It returns the standard formats, the line type the plan assigns and the area code region.
Digits with or without punctuation work. Numbers outside the US are read with the +country code.
Area code 512 at a glance
NANPA lists 785 central office codes (prefixes) in use in area code 512, held by 36 holders across 36 rate centers.
| Fact | Value |
|---|---|
| In service since | 1947-01-01 |
| Time zone | Central (C) |
| Assigned overlays | 737 (2013-07-01) |
| Prefixes in use | 785 |
| Pooled prefixes | 523 (67%) |
| Rate centers | 36 |
| Companies holding prefixes | 36 |
| Assignment dates on file | 2001-01-08 to 2024-11-01 (225 prefixes) |
| ZIP codes in its places | 107 |
Rate centers in area code 512
The largest rate center is AUSTIN, with 585 prefixes (75%).
| Rate center | Prefixes | Share |
|---|---|---|
| AUSTIN | 585 | 75% |
| GEORGETOWN | 29 | 4% |
| SAN MARCOS | 26 | 3% |
| BASTROP | 19 | 2% |
| LEANDER | 12 | 2% |
| LOCKHART | 11 | 1% |
| BURNET | 8 | 1% |
| TAYLOR | 7 | <1% |
| 28 other rate centers | 88 | 11% |
Who holds the prefixes in 512
Southwestern Bell holds the most prefixes, 273 (35%). 67% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
| Holder | Prefixes | Share |
|---|---|---|
| Southwestern Bell | 273 | 35% |
| New Cingular Wireless PCS | 98 | 12% |
| T-Mobile USA | 70 | 9% |
| Verizon Wireless | 49 | 6% |
| Level 3 Of Telecom Of Texas | 45 | 6% |
| Frontier Comm Of Texas | 37 | 5% |
| 30 other carriers | 213 | 27% |
A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company. Find which carrier a number is on, or browse the prefix holders.
History of area code 512
- 1947-01-01 Area code 512 went into service.
- 1992-11-01 Area code 210 went into service and names 512 as its parent.
- 1999-02-13 Area code 361 went into service and names 512 as its parent.
- 2013-07-01 Area code 737 went into service as an overlay in the same area as 512.
Area codes nearest to 512
Distance is measured between the centers of the ZIP code places each area code serves, so it is a rough guide.
Overlay codes in the same area
ZIP codes in area code 512
107 ZIP codes fall in places that have a rate center in this area code.
| Place | ZIP codes |
|---|---|
| Austin, TX | 74 |
| Georgetown, TX | 4 |
| Leander, TX | 3 |
A ZIP code and an area code are unrelated systems. A ZIP code can sit in more than one area code, and an area code spans many ZIP codes.
Complaints on file for 512 numbers
5,814 FCC complaints are on file for 4,249 numbers in 512, most often filed as "Unwanted Calls". These are unverified consumer reports.
| Year of latest complaint | Numbers |
|---|---|
| 2023 | 185 |
| 2024 | 155 |
| 2025 | 204 |
Other area codes in Texas
Texas is one state with 29 area codes in the NANPA table. 512 is one of them.
Next to 512 in the numbering table
These are the codes just before and after 512 when all are sorted by number. They are neighbours on the list, not necessarily on the map.
What the area code does and does not tell you
A number that starts with 512 was first assigned in Texas. That is a fact about where the number began, and it is a useful hint when you check a form entry, for example a billing address in Texas next to a 512 phone number.
It does not show where the person is today. A number stays with its owner after a move or a change of provider (number portability), and mobile numbers travel with the handset. The area code also cannot tell you whether the line is active, who the carrier is, or whether the number is mobile or fixed: the plan shares those ranges. Read more about the area code, the numbering plan and line type.
Check numbers in bulk with the API
| Product | Credits | Docs |
|---|---|---|
| Phone Numbering-Plan Validation | 1 credit per valid number | API docs |
| Phone Intelligence (carrier and line status) | 1 credit per check (invalid numbers outside the US and Canada are free) | Product page |
Questions about area code 512
Where is area code 512?
NANPA assigns area code 512 to Texas, United States.
In which state does area code 512 sit?
Texas. 512 is one of 29 area codes the NANPA table assigns to the state.
Which places does area code 512 cover?
The places with the most ZIP codes among the rate centers in 512 are Austin, TX, Georgetown, TX and Leander, TX. The rate center list on this page shows all of them.
Who owns area code 512?
NANPA assigns area codes. Within 512, Southwestern Bell holds the most prefixes, 273 prefixes or 35%.
Which time zone does 512 use?
The NANPA NPA report lists the time zone for 512 as Central (C).
What year did 512 enter service?
The NANPA NPA report gives an in-service date of 1947-01-01, so 512 has been in use since 1947.
Does area code 512 have an overlay?
Yes. 737 (in service 2013-07-01) shares the same area with 512, so numbers from all of them are local to each other.
Which area codes are nearest to 512?
The area codes closest to 512, measured between the centers of the ZIP code places they serve, are 210 (about 76 miles), 726 (about 76 miles), 830 (about 86 miles), 254 (about 89 miles) and 979 (about 93 miles).
How many prefixes does area code 512 have?
NANPA's report dated 2026-10-17 lists 785 prefixes in service in 512, spread over 36 rate centers and 36 holders.
Are there complaints about 512 numbers?
The FCC data on file has 5,814 complaints for 4,249 numbers in 512. They are unverified consumer reports. A number with no complaints on file is not proven safe.
Area code assignments: North American Numbering Plan Administrator NPA report, file dated 10/17/2026, retrieved 2026-10-17. Source file. New codes are assigned several times a year. Prefixes, rate centers, holders, time zone, in-service date and overlays: NANPA central office code report dated 2026-10-17 and NPA report dated 2026-10-18. Complaints: FCC consumer complaints open data, fetched 2026-10-17. ZIP code places: Postal code places and coordinates: GeoNames (geonames.org), licensed CC BY 4.0.