Round Rock, Texas electricity: Oncor wires, 4 split ZIP codes to check
Round Rock is Oncor country between two city-owned utilities, Austin Energy to the south and Georgetown to the north.
Last updated . Written by Power Hopper. Reviewed by Brent Ward, founder, on 2026-10-19. Data as of October 5, 2026 (meters) and October 19, 2026 (plan prices).
In short: Every Round Rock-addressed home in ERCOT's competitive data is on Oncor's wires (72,407 active residential meters, October 5, 2026). Most Round Rock addresses can choose a retail provider, but 4 of the ZIP codes below are split, so check your exact address. Your delivery utility handles the wires and outages; the retail provider you choose sets your price and sends the bill.
Who delivers electricity in Round Rock?
Every Round Rock-addressed home in ERCOT's competitive data is on Oncor's wires (72,407 active residential meters, October 5, 2026). The delivery utility (TDU) owns the poles and wires, reads the meter and restores power; in an outage, contact Oncor at oncor.com/outages, not your retail provider.
Oncor delivery charges and area
Can every address in Round Rock choose an electricity provider?
Most Round Rock addresses can choose a retail provider, but 4 of the ZIP codes below are split, so check your exact address.
EIA’s 2024 utility data also lists these utilities in Williamson, Travis counties: electric co-ops Bartlett Electric Coop, Inc, Bluebonnet Electric Coop, Inc, Pedernales Electric Coop, Inc. EIA reports them by county, not by street, so some may not reach Round Rock itself; addresses they serve do not have retail choice unless the utility opted in.
Meter counts use the postal city on the service address, which is not the same as city limits. Source: ERCOT TDSP ESIID Extract (October 5, 2026); EIA-861 (2024).
Moving to Round Rock
Local numbers for setting up a home in Round Rock, each checked on the official source. More contacts, and a printable list, are on Round Rock helpful move-in information.
- Water and utility billing: utility billing (start, transfer or stop water service), 512-218-5460.
- Trash pickup: Republic Services: trash and recycling, 512-255-4980.
- Natural gas: Atmos Energy: customer service, 888-286-6700.
- Public schools: Round Rock ISD.
- Driver license: Texas DPS Driver License Office: Georgetown, 512-424-2600.
You enter your address on the next screen, and we confirm there whether you can choose an electricity provider at that address.
Have a High Light Bill or Electric Bill?
If your electricity bill in Round Rock came in higher than you expected, upload or enter it and see whether another plan could lower your electricity costs, or whether staying where you are makes more sense.
Weather and electricity in Round Rock
Typical weather near Round Rock, from the nearest NOAA station with a complete 1991-2020 record: Austin Great Hills, about 10 miles from the city center (station elevation 880 ft). These are normals for that station, not readings at your address. August is the warmest month on average, with a normal daily high of 96°F; January has the coolest average low, 38°F. Average daily highs reach 90°F or more in June to August. No month averages a daily low at or below freezing.
For electricity, the normals point to two seasons that can lift a household's usage: cooling-degree days (a measure of how far each day's mean temperature sits above 65°F) peak in August at 600 for the month, and heating-degree days (below 65°F) peak in January at 510. How much that matters to a bill depends on the home, its insulation, its heating fuel and the household, so use your own usage history, not a regional average, when you compare plans.
| Month | Avg high °F | Avg low °F | Precipitation (in) | Cooling degree-days | Heating degree-days |
|---|---|---|---|---|---|
| Jan | 60 | 38 | 2.6 | 3 | 510 |
| Feb | 65 | 41 | 2.0 | 12 | 344 |
| Mar | 72 | 48 | 3.0 | 43 | 202 |
| Apr | 79 | 55 | 2.3 | 116 | 62 |
| May | 84 | 64 | 4.1 | 290 | 10 |
| Jun | 92 | 70 | 4.4 | 492 | 0 |
| Jul | 96 | 73 | 2.8 | 594 | 0 |
| Aug | 96 | 72 | 2.3 | 600 | 0 |
| Sep | 89 | 67 | 3.4 | 390 | 2 |
| Oct | 80 | 57 | 4.6 | 169 | 56 |
| Nov | 69 | 47 | 2.8 | 33 | 249 |
| Dec | 61 | 39 | 2.8 | 4 | 470 |
Historical weather records for Williamson County
The Texas Railroad Commission's county table lists a record low of -5°F (1949) and a record high of 113°F (1917), and a regional estimate of 24 consecutive hours as a typical longest freezing or frozen-precipitation period for Williamson County. These are historical county extremes, not Round Rock's monthly averages and not a forecast; the normals above describe ordinary months.
Reference only: the U.S. Energy Information Administration's 2020 Residential Energy Consumption Survey puts the average Texas household at about 13,440 kWh a year (about 1,120 kWh a month if spread evenly). That is a statewide average for 2020, not Round Rock, and not an estimate for your home. EIA source.
Sources: NOAA NCEI U.S. Climate Normals 1991-2020, station USC00410433; Texas Railroad Commission, Historical Weather Data by County (2022).
What is different about electricity in Round Rock?
- ZIP 78728 is split: Austin city limits cover about 39% of its land, and Austin Energy customers cannot choose a retail provider; ERCOT still lists 11,156 Oncor homes there, 629 with a Round Rock address. Source: Austin Energy (City of Austin utility); Census 2020 ZCTA-to-place relationship file.
- The City of Round Rock’s utility-billing page lists the city for water, wastewater, garbage and recycling, Atmos Energy for gas, and says: “Oncor delivers the electricity. Residents choose the provider of their services for billing.” Source: City of Round Rock: Utility Billing.
- To the north, Georgetown Utility Systems is city-owned and has no retail choice; ZIP 78628 shows 13 competitive meters for about 19,084 households. Source: Georgetown Utility Systems (city-owned).
Round Rock electricity by the numbers
| Measure | Value | Source |
|---|---|---|
| Population (July 1, 2025 estimate) | 141,282 | Census Vintage 2025 city and town population estimates |
| Population (2020 estimates base) | 119,523 | Census Vintage 2025 city and town population estimates |
| Occupied households (ACS 2020-2024) | 48,647 | Census ACS 2020-2024 5-year estimates |
| Active residential meters with a Round Rock address | 72,407 | ERCOT TDSP ESIID Extract |
| Active business meters with a Round Rock address | 7,589 | ERCOT TDSP ESIID Extract |
| Residential meters per Census household | 1.49 | ERCOT TDSP ESIID Extract |
| Delivery utilities (homes) | Oncor 72,407 | ERCOT TDSP ESIID Extract |
| Counties | Williamson, Travis | Census 2020 ZCTA-to-place and ZCTA-to-county relationship files |
| ZIP codes touching Round Rock | 9 | Census 2020 ZCTA-to-place and ZCTA-to-county relationship files |
| Split ZIP codes (flagged below) | 4 | ERCOT TDSP ESIID Extract |
One ESI ID (meter) per home or apartment with service. A ratio above 1 usually means vacant, seasonal, new or unincorporated homes using the Round Rock mailing address; below 1 means some homes are served outside the competitive market. How we built these numbers. Download: Round Rock ZIP table (CSV).
What do electricity plans cost in Round Rock right now?
Fixed-rate residential medians from Power to Choose, Oct 19, 2026, 7:59 AM CT (Oncor: 170 listings). Prices include delivery. A median is not a quote.
| Delivery utility | 500 kWh | 1,000 kWh | 2,000 kWh | Delivery charge |
|---|---|---|---|---|
| Oncor | 14.1¢ | 13.4¢ | 13.2¢ | 6.8673¢/kWh + $4.06/mo (effective October 4, 2026; tariff) |
Source: Power to Choose export, Oct 19, 2026, 7:59 AM CT; method in Texas rates.
Round Rock ZIP codes: how much of each is on the competitive market?
Not every address in these ZIP codes has retail choice; check your exact address. ZIP codes cross city limits and utility lines. The ratio compares competitive residential meters with Census households in the whole ZIP; it is an estimate, not an address check.
| ZIP | Main postal cities (homes) | ZIP land inside Round Rock | Competitive homes (ERCOT) | Households (Census) | Ratio | What it means |
|---|---|---|---|---|---|---|
| 78665 | Round Rock 29,155, Pflugerville 1 | 61% | 29,157 | 24,162 | 1.21 | Most homes are on the competitive market. |
| 78664 | Round Rock 23,644, Pflugerville 918 | 72% | 24,563 | 23,484 | 1.05 | Most homes are on the competitive market. |
| 78634 | Hutto 23,298, Round Rock 254, Taylor 4 | 0% | 23,556 | 15,808 | 1.49 | Most homes are on the competitive market. More meters than year-round households: vacant, seasonal, new or recently built homes. 17 new residential meters Oct 7-18, 2026. Mostly outside Round Rock city limits. |
| 78681 | Round Rock 18,081, Austin 333 | 45% | 18,414 | 20,135 | 0.91 | Most homes are on the competitive market. |
| 78626 | Georgetown 11,462, Round Rock 123, Weir 12 | 0% | 11,605 | 16,813 | 0.69 | Split. Most, but not all, homes are on the competitive market. Split: City of Georgetown (Georgetown city limits cover about 23% of the ZIP's land); that utility's customers can't choose. 16 new residential meters Oct 7-18, 2026. Mostly outside Round Rock city limits. |
| 78728 | Austin 10,480, Round Rock 629, Pflugerville 47 | 5% | 11,156 | 13,169 | 0.85 | Split. Most homes are on the competitive market. Split: Austin Energy (Austin city limits cover about 39% of the ZIP's land); that utility's customers can't choose. Mostly outside Round Rock city limits. |
| 78717 | Austin 1,802, Round Rock 371 | 0% | 2,173 | 14,939 | 0.15 | Split. Few homes are on the competitive market. Split: Austin Energy (Austin city limits cover about 72% of the ZIP's land); that utility's customers can't choose. Mostly outside Round Rock city limits. |
| 78653 | Manor 1,433, Round Rock 85, Pflugerville 26 | 0% | 1,570 | 14,612 | 0.11 | Split. Few homes are on the competitive market. Split: Austin Energy (Austin city limits cover about 7% of the ZIP's land); that utility's customers can't choose. Mostly outside Round Rock city limits. |
| 78680 | Round Rock 59 | 0% | 59 | n/a | n/a | PO box or special ZIP; no household count to compare. Mostly outside Round Rock city limits. |
Split ZIP codes for Round Rock: 78728, 78717, 78626, 78653.
Sources: ERCOT TDSP ESIID Extract (Oct 5, 2026); Census ACS 2020-2024; Census ZCTA relationship files.
Homes, renters and electric bills in Round Rock’s ZIP codes
Among Round Rock’s main ZIP codes, 78634 has the largest share of households paying $250 or more a month for electricity (27.4%); 78728 has the most renters (70.9% of households); 78634 has the newest housing (17.7% built in 2020 or later). High-bill shares reflect home size, age and heating type as much as price, so they are a reason to check your usage, not a verdict on any provider.
| ZIP | Renter households | Moved in the past year | Electric bill $250+/month | Built 2020 or later | New meters Oct 7-18, 2026 |
|---|---|---|---|---|---|
| 78665 | 38.6% | 22.8% | 22.3% | 12.3% | 5 |
| 78664 | 46.3% | 17.2% | 18.7% | 2.2% | 0 |
| 78681 | 26.1% | 11.6% | 24.1% | 2.8% | 0 |
| 78728 | 70.9% | 19.7% | 12.2% | 4.4% | 0 |
| 78717 | 48.7% | 20.9% | 14.6% | 8.3% | 0 |
| 78634 | 21.4% | 13.5% | 27.4% | 17.7% | 17 |
| 78626 | 38.2% | 22.2% | 25.0% | 16.0% | 16 |
Census ACS 2020-2024 5-year, ZCTA level: B25003 (tenure), B07003 (moved), B25132 (electricity cost, households charged for electricity), B25034 (year built); new meters from ERCOT daily ESIID files. Compiled in Power Hopper’s Oct 18, 2026 ZIP study.
How do towns near Round Rock compare?
Neighboring cities and towns within about 28 miles, by distance from Round Rock’s center. Status is our whole-place estimate; check your exact address.
| Town | Distance | Population | Competitive homes (postal city) | Delivery utility | Status |
|---|---|---|---|---|---|
| Pflugerville | 7 mi | 68,316 | 41,772 | Oncor | Most addresses can choose |
| Hutto | 7 mi | 46,048 | 23,298 | Oncor | Most addresses can choose |
| Cedar Park | 9 mi | 79,032 | 0 | — | Few or none can choose |
| Georgetown | 10 mi | 106,907 | 11,520 | Oncor | Partly; city utility serves the rest |
| Leander | 12 mi | 91,132 | 0 | — | Few or none can choose |
| Manor | 13 mi | 23,070 | 1,436 | Oncor | Partly |
Business electricity in Round Rock
ERCOT lists 7,589 active business meters with a Round Rock address, about one for every 9.5 homes, and 39 meters in ERCOT’s large non-residential class across Round Rock’s main ZIP codes. On Oncor’s wires, a business picks its retail provider the same way a home does; larger accounts can also buy from suppliers that sell directly to commercial customers.
Power Hopper compares offers from retail electric providers and direct suppliers for businesses. For high-consumption businesses, we can run a competitive bid so more than one supplier prices the same usage. We can’t promise savings or how many suppliers will bid. Businesses in Texas retail-choice areas can request a rate review online.
How do I compare electricity plans in Round Rock?
Enter a Round Rock ZIP code, then your service address. If the address can shop, you’ll see plans; read each plan’s Electricity Facts Label (price at your usage, base charge, credits, term, cancellation fee) before you choose.
Common questions about electricity in Round Rock
Does the City of Round Rock provide electricity?
No. The city provides water, wastewater, drainage and garbage service. Its utility-billing page says Oncor delivers the electricity and residents choose the provider that bills them; Atmos Energy provides gas.
Is Round Rock Oncor or Austin Energy?
Round Rock-addressed homes in ERCOT's data are all Oncor (72,407 on October 5, 2026). Austin Energy serves inside Austin city limits, which cover about 39% of ZIP 78728 next door.
Can I choose my electricity provider in Round Rock?
Yes on Oncor's wires. Some homes on the edges are served by Pedernales or Bluebonnet electric co-ops, which don't offer choice. Check your exact address.
Which Round Rock ZIP has the most homes on the market?
78665 (29,157 competitive meters), then 78664 (24,563) and 78681 (18,414), per ERCOT's October 5, 2026 data.
Is ZIP 78681 Round Rock or Austin?
Mostly Round Rock by mailing address: 18,081 of its 18,414 competitive homes use Round Rock and 333 use Austin, all on Oncor’s wires, and about 45% of the ZIP’s land is inside Round Rock city limits. Austin Energy territory begins farther south, in ZIPs such as 78728.
Where to next?
Up: Oncor area · Williamson County · Travis County · Regional page
Nearest town pages: Pflugerville · Hutto · Killeen · Temple · Waco · Victoria · Sugar Land · Waxahachie
Compare plans · Moving · High bill · Texas rates · Areas without retail choice · Methodology
Sources
- ERCOT TDSP ESIID Extract (report 203): full extract as of Oct 5, 2026; daily files Oct 7-18, 2026
- Census ACS 2020-2024 5-year estimates (B25003 households, B01003 population)
- Census Vintage 2025 city and town population estimates
- Census 2020 ZCTA-to-place and ZCTA-to-county relationship files
- EIA-861 (2024) utility service territories by county
- PUCT Power to Choose residential offer export, Oct 19, 2026, 7:59 AM CT
- PUCT: Choosing an Electric Plan
- PUCT broker directory (BR260201)
- Oncor Electric Delivery
- Oncor delivery tariff (effective October 4, 2026)
- Austin Energy (City of Austin utility)
- City of Round Rock: Utility Billing
- Georgetown Utility Systems (city-owned)
BJW Ventures LLC d/b/a Power Hopper | PUCT BR260201. PUCT registration is not an endorsement.