What is a TDSP? Texas Transmission and Distribution Service Providers Explained
5 minute read · Texas electricity basics
Most Texans know who they buy electricity from — Reliant, TXU, Gexa, or any of the 100+ retail providers competing for their business. Fewer know who actually delivers that electricity to their home, or why it matters when shopping for a plan.
That entity is your Transmission and Distribution Service Provider, or TDSP. Understanding the distinction between your TDSP and your electricity provider is key to making sense of your bill and knowing which plans are available to you.
REP vs TDSP: the key difference
Texas deregulated its electricity market in 2002, separating two functions that used to belong to one company:
The company you have a contract with. They buy electricity on the wholesale market and sell it to you at a retail rate. You can choose your REP and switch freely.
The company that owns and maintains the physical infrastructure — poles, wires, transformers, and meters — that delivers electricity to your home. You cannot choose your TDSP; it's determined by your location.
When you switch electricity providers, only your REP changes. Your TDSP stays the same — the wires to your home don't change ownership. If there's a power outage in your neighborhood, you call the TDSP, not your electricity provider.
The 5 Texas TDSPs
Texas has five investor-owned TDSPs operating in the deregulated ERCOT market. Each serves a distinct geographic area:
| TDSP | Service Area | Major Cities |
|---|---|---|
| Oncor | North & West Texas | Dallas, Fort Worth, Arlington, Plano, Waco |
| CenterPoint Energy | Southeast Texas | Houston, Sugar Land, The Woodlands, Katy |
| AEP Texas Central | South Texas | Corpus Christi, McAllen, Laredo, Victoria |
| AEP Texas North | West Texas | Abilene, Midland, Odessa, Lubbock, Amarillo |
| Texas-New Mexico Power (TNMP) | Parts of Southeast & North Texas | Galveston, Texas City, Lewisville |
Your TDSP determines two important things: which retail electricity providers are licensed to serve your address, and what the TDU delivery charge on your bill will be. Delivery charges vary by TDSP and are the same regardless of which REP you choose.
What about Austin, San Antonio, and other cities?
Not all of Texas is deregulated. Several major cities are served by municipal utilities or electric cooperatives that are exempt from retail competition:
- Austin Energy — serves Austin and surrounding areas
- CPS Energy — serves San Antonio
- Entergy Texas — serves Beaumont and parts of East Texas (regulated)
- Lubbock Power & Light — recently joined ERCOT but retail competition not yet available
Customers in these areas cannot choose their electricity provider and are not part of the deregulated market. If you enter a ZIP code in one of these areas on Texas Energy Compare, we'll let you know it's outside the deregulated market.
Why your TDSP matters when shopping
When you search for electricity plans by ZIP code, the results are filtered to only show plans that are available in your TDSP's service area. A plan available in Dallas (Oncor) may not be offered in Houston (CenterPoint) — providers choose which TDSPs to operate in and file separate rates for each.
Texas Energy Compare identifies your TDSP automatically from your ZIP code so you only see plans that are actually available to you. Enter your ZIP code below to get started.