What is a TDU, and which one serves you?

Delivering electricity to your address, maintaining the lines and substations that carry it, owning and reading your meter, and restoring service after an outage. If your power is out, your TDU is who is fixing it — not your retailer.

It also charges for that service. The delivery portion of your bill goes to the TDU at rates approved by the state regulator, and every customer in a territory pays the same delivery rates regardless of which retailer they buy from.

Oncor is the largest, covering much of North and West Texas including Dallas–Fort Worth. CenterPoint covers the Houston area and much of the upper Gulf Coast. AEP Texas Central covers South Texas and the central coast around Corpus Christi and the Rio Grande Valley. AEP Texas North covers a large, thinly populated stretch of West and North-Central Texas around Abilene and San Angelo. Texas-New Mexico Power serves a set of separated pockets rather than one region, including parts of the Gulf Coast and West Texas.

Each has its own page on this site with current inventory sampled in its area, and each of those pages says which places it is commonly identified with.

Retailers choose which delivery territories to sell in, and price separately for each, because the delivery costs and the customer base differ. So the plan list at a Houston address and the plan list at a Dallas address are genuinely different products, not the same offers relabelled.

It also means a city name is not enough to identify your options. City boundaries and utility boundaries do not agree — several Texas cities span two territories, and some cities sit next to municipal utilities where there is no retail choice at all. Your ZIP code is what settles it.