Round Rock Electricity Rates, Explained
By the TexasPowerCost Editorial Team — independent Texas electricity analysis · Last reviewed October 18, 2026 · how we analyze plans
Just want the cheapest plan? This guide explains how Round Rock electricity rates actually work. To rank today’s live plans by your real usage, use the Round Rock rate comparison tool →
Last updated: October 18, 2026 · 7 min read
Round Rock is one of the fastest-growing cities in the United States — a Williamson County suburb north of Austin that has expanded rapidly with major employers including Dell Technologies, Apple, and Kalahari Resorts. Despite sitting just north of Austin, Round Rock residents have something Austin residents do not: the ability to shop for competitive electricity plans. Round Rock is Oncor Electric Delivery territory, fully within the deregulated Texas electricity market. This guide covers how to find the lowest-cost plan, what Oncor TDSP charges look like, and why your ZIP matters.
The short answer
Round Rock ZIP codes 78664, 78665, 78681, and 78682 are Oncor Electric Delivery territory — fully deregulated. Fixed-rate plans as of May 2026 advertise 9.5–13.5¢/kWh at 1,000 kWh. Central Texas summers drive 1,000–1,600 kWh usage for a typical 3-bedroom home. Enter your ZIP and bedroom count for the true interpolated cost at your real usage level.
Round Rock vs. Austin — A Key Difference
Austin is served by Austin Energy, a city-owned municipal utility. Austin residents pay rates set by the Austin City Council and cannot choose a different electricity provider. Round Rock, which abuts Austin to the north, is in Williamson County — a different political jurisdiction served by Oncor Electric Delivery, an investor-owned TDU operating within the deregulated ERCOT market.
This means that moving from Austin to Round Rock changes your electricity options entirely. In Austin, you get one rate structure from one provider. In Round Rock, you can compare dozens of plans from multiple REPs and lock in a fixed rate that the market competition keeps honest. If you are moving to the Austin area and want competitive electricity options, Williamson County addresses (Round Rock, Cedar Park portions, Pflugerville portions) are worth confirming against the deregulation map.
Oncor TDSP Charges in Round Rock
Every Round Rock electricity bill includes Oncor Electric Delivery's regulated TDSP charges, regardless of which REP you choose. These charges consist of a fixed monthly customer charge and a per-kWh distribution fee. At 1,000 kWh, Oncor TDSP charges typically add $10–$14 to your bill. At 1,500 kWh in peak summer, they rise to $15–$21.
TDSP charges are the same across all Oncor territory — Dallas, Fort Worth, Plano, and Round Rock all pay the same Oncor delivery rates. The competitive REP energy charge is where variation occurs — and where shopping saves money.
Round Rock ZIP Codes and Usage Profiles
| ZIP | Area | Typical Housing | Summer Usage |
|---|---|---|---|
| 78664 | Central Round Rock | 1980s–2000s, 1,200–2,000 sq ft | 1,000–1,500 kWh |
| 78665 | East Round Rock / Hutto border | 2000s–2020s, 1,600–2,800 sq ft | 1,200–1,800 kWh |
| 78681 | West Round Rock / Brushy Creek | 1990s–2010s, 1,400–2,400 sq ft | 1,100–1,600 kWh |
| 78682 | North Round Rock / Teravista | 2000s–2020s, 1,800–3,200 sq ft | 1,400–2,200 kWh |
A Texas example
Marcus moved to Round Rock (78682, Teravista) from an Austin apartment. In Austin he paid Austin Energy's tiered rate with no plan choices. In his new 2,400 sq ft Round Rock home, August usage hit 1,780 kWh. His builder-default REP charged a variable rate that reached 14.2¢/kWh that August. Total bill: $296.40 before taxes and Oncor charges. After shopping the deregulated market and switching to a 12-month fixed plan at 10.8¢/kWh (2,000 kWh tier), his next August bill came to $221.15 — a $75.25 saving in a single month just by using the competitive market he now had access to.
Comparing Plans in Round Rock — What to Look For
Round Rock's housing stock skews newer and larger than Austin proper, particularly in 78665 and 78682 where master-planned communities like Teravista and Avery Ranch have high-square-footage homes. This means summer usage frequently pushes above 1,500 kWh — the range where bill-credit plans that look attractive at exactly 1,000 kWh become more expensive than flat fixed-rate plans.
When comparing plans, use your actual usage level — not the advertised 1,000 kWh rate. A plan advertising 9.5¢/kWh with a $50 bill credit at 1,000 kWh may calculate to 14.5¢ effective at 800 kWh, and revert to 12¢ at 1,400 kWh once the credit no longer fully applies. The search tool interpolates at your actual usage level to expose these traps.
The math
Round Rock home, August, 1,400 kWh. Plan A: 10.5¢ at 1,000 kWh, 9.8¢ at 2,000 kWh — interpolated rate at 1,400 kWh: 10.22¢, energy charge $143.08. Plan B: advertised 9.2¢ with a $40 bill credit at 1,000 kWh. At 1,400 kWh the credit doesn't scale — energy charge at 9.2¢ base = $128.80 minus only partial credit = ~$145.20. Plan A is cheaper by $2.12/month at 1,400 kWh, despite Plan B's better advertised rate. At 1,600 kWh the gap widens further.
Smart move for Round Rock homeowners
Round Rock's growth means many homes are in master-planned communities built with energy codes that have improved significantly between 2000 and 2020. If your home was built before 2006, it likely has older attic insulation standards (R-19 to R-22 in the attic vs. R-38 to R-49 in newer builds). Upgrading attic insulation is often the single highest-ROI efficiency investment available to Central Texas homeowners — the payback period is typically 3–6 years, and the savings compound with every year you stay on a competitive fixed-rate plan.
Key Takeaways
Round Rock ZIP codes 78664, 78665, 78681, and 78682 are Oncor territory — fully deregulated. Unlike nearby Austin, Round Rock residents can shop for competitive electricity plans. Summer usage in 1,000–1,800 kWh range is common depending on home size. Compare plans at your actual usage level, not the advertised 1,000 kWh rate. Newer large homes in 78665 and 78682 benefit most from comparing at the 2,000 kWh EFL tier.
Find the cheapest Round Rock plan for your home
Enter your ZIP and bedroom count — true interpolated cost at your actual usage level.
Compare Round Rock Plans →Frequently Asked Questions
Can Round Rock residents shop for electricity plans?
Yes. Round Rock is in Williamson County and is served by Oncor Electric Delivery — the same regulated TDU that serves Dallas and Fort Worth. Oncor territory is within the deregulated ERCOT market. Round Rock residents can choose from competitive retail electric providers and switch plans at any time. This is different from nearby Austin, which is served by Austin Energy (a municipal utility) where no competitive plans exist.
What ZIP codes in Round Rock are deregulated?
Round Rock's primary residential ZIP codes — 78664, 78665, 78681, and 78682 — are all Oncor Electric Delivery territory within the deregulated market. Enter your ZIP in the search tool to confirm and see the current ranked plan list for your specific address.
What are typical electricity rates in Round Rock?
As of May 2026, fixed-rate plans in Round Rock (Oncor territory) typically advertise 9.5–13.5 cents per kWh at 1,000 kWh. Round Rock's Central Texas climate drives summer usage of 1,000–1,600 kWh for a 3-bedroom home, depending on home size and age. The advertised 1,000 kWh rate understates real summer bills for most households — enter your ZIP and bedroom count for the true interpolated cost at your actual usage.
Who is the TDU for Round Rock electricity?
Oncor Electric Delivery is the regulated TDU for Round Rock in Williamson County. Oncor's TDSP charges — a fixed monthly customer fee and a per-kWh distribution charge — appear on every Round Rock electricity bill regardless of which retail electric provider you use. You cannot change your TDU, but you can freely shop for competitive REPs.
How does Round Rock electricity differ from Austin?
Austin is served by Austin Energy, a city-owned municipal utility — Austin residents cannot shop for competitive electricity plans. Round Rock is served by Oncor Electric Delivery and is in the deregulated ERCOT market — Round Rock residents can shop freely. If you are moving from Austin to Round Rock (or vice versa), your electricity options change significantly.
What is a typical summer electricity bill in Round Rock?
A 3-bedroom Round Rock home typically uses 1,100–1,500 kWh in July and August. At an all-in effective rate of 10–12 cents per kWh (energy plus Oncor TDSP plus taxes), summer bills typically run $130–$200. Newer large homes in Teravista or Avery Ranch may exceed 1,700 kWh and $220+ in peak summer months.
Your Next Move
Enter your Round Rock ZIP in the search tool for live plan comparisons. If you are curious why Austin residents one city over cannot shop, the Austin electricity rates guide explains Austin Energy's municipal structure. For the broader Oncor market, the Dallas electricity rates guide covers Oncor TDSP charges in depth. The True Cost Calculator models any plan at your actual usage level.
Small apartment (~600 kWh) · Large home (~2,000 kWh) · All Round Rock plans