Where does 512 cover?
The carrier notices for the 737 overlay describe 512 as generally the greater Austin area, principally in eight counties: Bastrop, Burnet, Caldwell, Hays, Lampasas, Milam, Travis and Williamson. The word "principally" is doing real work there, as the next section shows.
A 2012 carrier notice names the communities served. These are the larger ones:
Austin · Bastrop · Bee Cave · Buda · Burnet · Cedar Park · Dripping Springs · Elgin · Georgetown · Hutto · Kyle · Lakeway · Lampasas · Leander · Liberty Hill · Lockhart · Manor · Pflugerville · Rockdale · Round Rock · San Marcos · Smithville · Taylor · Wimberley
The notice also lists smaller places such as Jarrell, Kempner, Lometa and Thrall, so 512 reaches rural towns a long way from the Austin city limits. That list dates from 2012. Treat it as a guide to the territory rather than a closed roster.
Where does 512 stop?
County names mislead here, because a code's real edge is set by exchange, not by county. Burnet County is one of the eight, and the town of Burnet is 512, yet Marble Falls in the same county is 830. Caldwell County splits the same way: Lockhart is 512 and Luling is 830.
The Public Utility Commission of Texas exchange lists put these nearby towns outside 512:
| Direction from Austin | Town | Its code |
|---|---|---|
| South | San Antonio | 210, with 726 |
| South and south-east | New Braunfels, Seguin, Luling | 830 |
| West | Marble Falls, Fredericksburg, Kerrville, Boerne | 830 |
| North-west | Llano, Kingsland, San Saba | 325 |
| North | Killeen, Temple, Salado | 254 |
| East | Giddings, La Grange, Brenham, Bryan | 979 |
The line can fall between neighbours. San Marcos and New Braunfels are the next cities along the same interstate, and they have different codes.
512 vs 737: what is the difference?
Only the digits, and how old the number can be. 737 is an overlay, so it serves the same geographic area as 512 and nobody had to give up a number when it arrived.
| 512 | 737 | |
|---|---|---|
| In service | 1947 | 1 July 2013 |
| Area | The same map | |
| Oldest possible number | Decades old | July 2013 |
| Local dialing | Ten digits, between or within either code | |
| Call price | Unchanged by the overlay; local calls stayed local | |
Which code a new line gets comes down to the prefixes its carrier holds. You may be able to ask for one, but nothing in the overlay promises it. NANPA's April 2026 exhaust analysis projects the 512/737 area to last until the first quarter of 2044, so no third code is imminent. Long-range forecasts move, so read that date as "not soon" rather than as a deadline.
Why did 737 take 13 years to arrive?
NANPA's area code database shows 737 assigned on 25 April 2000 and in service on 1 July 2013. Compare Washington, D.C., where 771 went from assignment to service in about 14 months. Austin's first attempt stalled and was shelved for over a decade:
- 1947
512 begins
One of the original codes, in service from 1947. Its territory included what are now the 210 and 361 areas.
- 1992
210 splits off
San Antonio's 210 went into service on 1 November 1992. 830 came later, split from 210 in 1997 rather than from 512.
- 1999
361 splits off
Corpus Christi's 361 began on 13 February 1999, with a permissive period running to 18 September.
- 2000
737 planned the first time
A Texas PUC order in Project 21772 set a concentrated-growth overlay for 10 November 2001.
- 2001
Suspended
The overlay was suspended on 25 April 2001, NANPA's letter of 2 May records, about six months before it was due.
- 2012
Approved again
The Texas PUC approved an all-services overlay in Project 36899 on 28 June 2012. Ten-digit dialing became optional on 1 December.
- 2013
Ten digits, then 737
Ten-digit local dialing became mandatory on 1 June, and new lines could get 737 from 1 July.
The two plans differed in kind: the first was a concentrated-growth overlay, and the second covered all services. We haven't found a primary record explaining why the first was dropped, so we won't guess at one here.
How do you dial an Austin number?
| Calling | What to dial |
|---|---|
| Local, including 512 to 737 | Area code + seven digits |
| Toll | 1 + area code + seven digits |
| From another country | Exit code + 1 + 512 + seven digits |
| Service numbers | 911, 211, 311, 411, 511, 611, 711 and 811 — still three digits |
Seven digits stopped working on 1 June 2013: the call fails and a recording tells you to redial. NANPA's database and AT&T's notice agree on ten digits for local calls. One 2012 carrier notice said 1 + 10 in its summary, then ten digits in its own dates, so the older wording you may still find online isn't reliable.
The overlay hit equipment harder than people. AT&T's notice names PBXs, life-safety systems, alarm panels, gate entry and speed dialers as things to reprogram. Anything installed before 2013 and never touched again is where a stored seven-digit number can still be hiding. Our guide to area codes and call routing covers what to check.
Is 512 a country code?
No. There is no country code 512. A Texas number written in full is +1 512 followed by seven digits, where 1 is the country code. The trap is the reverse order: the ITU's list gives Peru country code 51, so a number beginning +51 2… is a Peruvian number, whatever it looks like at a glance.
What does a 512 number tell you?
Where the number was first issued, and little else. A 512 mobile keeps its code when its owner moves away, and a number can be held by someone who has never lived in Texas. The code also isn't evidence of who is calling, because caller ID can be set to a number the caller has no connection to, which the FCC calls spoofing. If an unexpected caller wants money or personal details, hang up and ring the organisation on a number you found yourself.
For a business calling out from an Austin number, the local code doesn't decide whether the number reaches the handset. CLI vs NCLI routes explains what does.
Which codes surround 512?
| Code | Main area | In service | Split from |
|---|---|---|---|
| 210 / 726 | San Antonio | 1 November 1992; 726 from 23 October 2017 | 512 |
| 830 | Hill Country and the south-western corridor | 7 July 1997 | 210 |
| 361 | Corpus Christi | 13 February 1999 | 512 |
| 254 | Killeen, Temple and Waco | 25 May 1997 | 817 |
| 325 | Abilene and the west-central counties | 5 April 2003 | 915 |
| 979 | Bryan and the Brazos valley | 19 February 2000 | 409 |
Dates and parent codes come from NANPA's database. Texas's other big metros have gone much further down the overlay road: 469 in Dallas is one of four codes on one map, and 832 in Houston is one of five. All our guides are on the US area codes page.
512 area code FAQ
Is San Antonio in the 512 area code?
No. San Antonio left 512 in 1992 and uses 210 and 726. New Braunfels, between the two cities, is 830.
What is area code 737?
A second code for the same map as 512. New Austin-area lines could get 737 numbers from 1 July 2013.
Is Round Rock 512?
Yes. Round Rock, Cedar Park, Pflugerville, Georgetown and Leander are all in the 512/737 area.
Do I need to dial 1 for a local call in Austin?
No. Local calls need the area code and the seven-digit number. The 1 is for toll calls.
Sources
- NANPA — Area code (NPA) database, file dated 5 November 2026
- NANPA — Planning Letter 438: 737 overlay of 512 (1 August 2012)
- NANPA — Planning Letter 233: first 512/737 overlay plan (5 July 2000)
- NANPA — Planning Letter 276: overlay suspended (2 May 2001)
- NANPA — Planning Letter NANP-154: 361 split from 512 (1 February 1999)
- AT&T — Texas 512/737 area code overlay information
- Granite Telecommunications — 737 overlay of 512, customer notification (2012)
- Public Utility Commission of Texas — Exchange list for area code 512
- NANPA — 2026-1 NPA exhaust analysis (April 2026)
- ITU — List of ITU-T E.164 assigned country codes
- FCC — Caller ID spoofing
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