ESI ID Lookup in Texas: How to Find Your Business's ESID

To look up your ESI ID in Texas, start with your electric bill. PUCT's billing rule requires a retail electric provider's bill to show the ESI ID along with your service address and account number. No bill on hand? Ask the REP that bills you, use your utility's lookup (Oncor runs a public address search), or have your broker confirm it. ESI ID, ESID and ESIID are three spellings of the same thing: the Electric Service Identifier.

The number looks simple, but businesses get it wrong more often than homeowners do. It identifies a point of delivery, not your company or your street address, so one building can carry several. Its length depends on your utility. And a lookup tool that returns a number has not proved the meter can switch providers. This guide covers all three, with a sample bill that shows where the ESI ID sits.

Where to Find Your ESI ID: The Short Answer

What Is an ESI ID (ESID)?

An ESI ID is the identifier the Texas retail market uses for a single point of delivery. The PUCT defines it as "the basic identifier assigned to each point of delivery used in the registration system and settlement system managed by ERCOT or another independent organization" (16 TAC §25.5), and ERCOT's Nodal Protocols use nearly the same wording, with "Service Delivery Point" in place of "point of delivery." Our Texas electricity glossary has the short definition. In practice, three things matter:

• Your TDU creates it, not ERCOT. ERCOT's Protocols make it "the TDSP's responsibility to create, assign, maintain and retire" each ESI ID. In the competitive market, your TDU is CenterPoint, Oncor, AEP Texas, TNMP, Lubbock Power & Light or Nueces Electric Cooperative. ERCOT registers the number and settles the market against it (Protocols §15.4.1).
• Your REP attaches to it. Only one REP of record can be assigned to an ESI ID at a time. When you switch providers, the REP of record changes and the ESI ID stays.
• It names the delivery point, not you. It is not your customer account, and strictly speaking it is not your address either, since one address can hold several ESI IDs.

If the split between the company that bills you and the company that delivers your power is new to you, read REP vs. TDU in Texas first.

ESI ID vs. Account Number vs. Meter Number

Forms often ask for all three, and they are easy to confuse. The PUCT bill rule lists the ESI ID and the account number as separate required items, and ERCOT's Protocols treat each meter's identification number as data the TDU maintains on the ESI ID record (§15.4.1.5).

Because the meter number is recorded on the ESI ID, replacing a meter normally updates that record while the ESI ID stays the same. ESI IDs can still change in rare cases. ERCOT's Retail Market Guide says that when one utility acquires another's territory, the gaining utility "will change the ESI IDs for the Premises acquired," and a TDU can retire an ESI ID. For the meter number and the device itself, see how to read a commercial electric meter.

How Many Digits Is an ESI ID? Decoding the Number

You will often read that an ESI ID is "17 or 22 digits." That leaves out two utilities. ERCOT's Protocols set a format, not a fixed length: the digits "10," then the utility's five-digit Department of Energy code, then up to 29 characters (0–9 and A–Z) assigned by the utility, with a maximum of 36 characters in total (§15.4.1).

Each utility settles on its own length within that format. We counted lengths and prefixes in ERCOT's public TDSP ESI ID Extract, using the full files posted September 7, 2026. Virtually every record follows the pattern below. A handful per utility differ.

Data as of September 2026. Current ESI IDs are almost all numeric, but the Protocols allow letters, so "characters" is the precise word. Oncor's business page calls its ESI ID "a unique 17-digit number," which is right for Oncor only.

The first seven characters tell you which utility delivers your power. That is the company behind the TDU delivery charges on your bill, and you can see where each one operates in ERCOT's deregulated regions.

One caution: a prefix does not prove a site can choose its provider. ERCOT's extract listing still posts legacy files for territories outside the ERCOT market, including Entergy Gulf States, SWEPCO and a file labeled "AEP Texas SP." None of them has an active record, and the AEP Texas SP file shares AEP Texas North's 1020404 prefix. More on that under When There Is No ESI ID.

Where to Find the ESI ID on a Commercial Electric Bill

PUCT's billing rule requires a REP's bill to include "the service address, electric service identifier (ESI), and account number of the customer" (16 TAC §25.479(c)(1)(D)). The rule doesn't fix where on the page it goes, so layouts vary by REP. Look in the account summary, the service-address block or the meter-information block, usually near the top of the first page.

If one bill covers several locations, look for an ESI ID listed with each service address. The rule governs REP bills in competitive areas. It does not cover a municipal utility or co-op billing customers in its own territory. Customers larger than the small-commercial class can also agree in writing to terms that differ from PUCT's customer protection rules (16 TAC §25.471(a)(3)), so if a large account's invoice doesn't show the ESI ID, ask the REP for it.

Two quick checks catch the common mix-ups. First, match the suite or unit in the service address to the space you actually occupy. Second, confirm that the first seven characters point to the utility you expect. For every other line on the page, see how to read your commercial electricity bill in Texas.

ESID Lookup Without a Bill: Your Options

Ask Your REP

For an existing account, the company that sends your bill is the quickest route. Oncor's own guidance says: "If you need assistance identifying your ESI ID, please contact your Retail Electric Provider (the company to which you pay your electric bill)."

Use Your Utility's Lookup

Oncor offers a public ESI ID lookup that searches by service address. Oncor business customers can also see premise details through its Powered by Oncor portal. For CenterPoint, AEP Texas, TNMP and LP&L addresses, ask the utility or your REP. Self-serve tools change, and we only point readers to ones we have checked.

Third-Party ESID Lookup Tools

The address-search widgets on energy websites draw on public ERCOT data. ERCOT's user guide describes the TDSP ESI ID Extract as a "public extract" of "non-proprietary data" whose "access is not restricted," posted as a monthly full file plus daily updates. A tool built on it is fine for a quick check. Before you rely on a result, confirm three things:

1. The status is Active. The extract also carries Inactive and De-Energized records.
2. The suite or unit matches. A multi-tenant address can return many ESI IDs.
3. The record isn't from a legacy territory. Old files for utilities outside the ERCOT market still post, with no active records.

New Construction or No Meter Yet

If the utility hasn't extended service to the site, there is nothing to look up. The TDU assigns the ESI ID and submits it to ERCOT's registration database as it extends service, and it needs ERCOT's accepted response before service can start (Protocols §15.4.1.4). Setting up electricity for a new business location covers the full sequence, the new-location checklist lists what to collect before quotes, and getting a new commercial electric meter in Texas covers the meter itself.

Smart Meter Texas Is for Usage, Not Lookup

Smart Meter Texas doesn't find your ESIID; it asks you for it. Account setup requires the full ESIID, the meter number and your REP, according to the Smart Meter Texas residential user guide. Once you're in, the portal shows up to two years of data, with reports that include 15-minute intervals, daily meter reads and monthly billing information. You can export them as CSV or Green Button XML. It also lists the energy data sharing agreements you have with competitive service providers and lets you end them.

PUCT's advanced-metering rule requires 15-minute (or shorter) interval data to reach the portal on a day-after basis, accessible to the customer, the REP of record and entities the customer authorizes (16 TAC §25.130). Large sites may be on a different path. ERCOT requires an interval data recorder where peak demand is greater than 700 kW (700 kVA in CenterPoint's territory) or service is at transmission voltage above 60 kV (Protocols §18.6.1). Those sites' interval data may come through the utility's interval data recorder channel or the REP rather than the portal. For what to do with interval data once you have it, see finding your 15-minute peak.

Why One Business Can Have Many ESI IDs

ERCOT's Protocols assign "each metered Service Delivery Point" an ESI ID "corresponding to an existing billing meter" (§15.4.1.2). Oncor puts it plainly: "If a property has multiple meters at one address … each meter will have a separate ESI ID." A single commercial address can carry separate ESI IDs for:

• individual tenant suites;
• exterior signs and parking lot lighting;
• irrigation; and
• fire pumps.

Three exceptions break the one-meter, one-ID shortcut:

• Aggregated meters. The TDU may combine meters into one ESI ID only when every condition holds: the same customer and service address; the same load profile, or all interval-metered; the same voltage, UFE zone and load zone; and a tariff that allows it. You can ask the TDU for separate ESI IDs where its tariff allows.
• Submeters. A submeter whose usage is already counted inside another ESI ID gets none. That is why a suite behind a landlord's master meter may have nothing to enroll, the same situation master-metered apartment buildings face.
• Very large loads. A delivery point with load above 1 MW may be split into up to four virtual meters, each with its own ESI ID (§15.4.1.3).

For scale, ERCOT's September 7, 2026 extract files show about 1.18 million active ESI IDs labeled Small Non-Residential, and about 5,400 labeled Large Non-Residential, across the seven utilities in the table above. Those are ERCOT registration labels. They are not the same thing as the PUCT's small-commercial customer class.

The habit that follows: keep one row per ESI ID, not one per address, in your energy inventory. It is groundwork for switching commercial electricity providers, and the backbone of a multifamily renewal inventory.

What Your ESI ID Tells a Supplier, and What It Doesn't

The public ESI ID record shows the service address, the status (Active, Inactive or De-Energized), the premise type (Residential, Small Non-Residential or Large Non-Residential), the serving substation, the meter read cycle, and flags for advanced metering.

It does not show usage, demand history, the customer's name, the contract or the price. A supplier pricing a commercial account needs usage history. PUCT's advanced-metering rule opens portal access to that data only to the customer, the REP of record and parties the customer authorizes. For why peak demand matters as much as total usage, see kW vs. kWh on commercial electricity bills.

Why a Broker Asks for Your ESI ID

REPs price and enroll accounts by ESI ID. PUCT's enrollment rule has the REP collect the ESI ID "if available," so an enrollment can start from a service address, but the ESI ID removes the ambiguity (16 TAC §25.474). That matters most at multi-tenant sites, where enrolling the neighboring suite's meter is an expensive mistake to unwind. The new-location setup guide shows how that happens.

When you send Elite a bill, we use each ESI ID to confirm the delivery utility and premise type before we request pricing. Pulling your usage history takes your written authorization, usually a letter of authorization. We then shop the account across 25+ REPs, and the REP pays us, not you. Why Texas businesses use energy brokers explains the model.

Is It Safe to Share Your ESI ID?

Share it with the REP or broker you are actually working with, the way you would any account detail. For context, ESI IDs and service addresses already appear in ERCOT's public, non-proprietary extract. The number alone doesn't expose your usage: Smart Meter Texas also asks for the meter number and your REP, and third-party access to your data runs through agreements you approve. Changing your provider still requires your authorization and verification under PUCT's enrollment rule, §25.474.

When There Is No ESI ID

ERCOT's registration database covers "all metered and unmetered Electric Service Identifiers (ESI IDs) in Texas for Customer Choice" (Protocols §15). A meter outside a retail-choice area usually has no ESI ID at all:

• Municipal utilities and co-ops that haven't opted in. Meters served by Austin Energy, CPS Energy or CoServ are not in the registry, and the business buys its power from that utility.
• The opt-in exceptions. Lubbock Power & Light, whose customers gained retail choice in 2024, and Nueces Electric Cooperative are in the registry and do have ESI IDs.
• Outside the ERCOT market. Areas served by regulated utilities such as Entergy Texas and SWEPCO show only legacy records, none of them Active.

So what settles whether you can shop is an Active ESI ID from a competitive ERCOT utility, not any number a lookup tool returns. For where Texas businesses can choose, see deregulated energy states and cities in Texas.

ESI ID Frequently Asked Questions

How many digits is an ESI ID?

It depends on the utility. In ERCOT's public extract files posted September 7, 2026, CenterPoint ESI IDs are 22 characters; Oncor, AEP Texas and TNMP ESI IDs are 17; and Lubbock Power & Light and Nueces Electric Cooperative ESI IDs are 15. ERCOT's Protocols allow up to 36 characters, including letters, although current ESI IDs are almost all numeric.

Is the ESI ID printed on my meter?

Look for it on your bill, not on the meter. The meter carries its own meter number, which is a different identifier. PUCT's billing rule requires a REP bill to show the ESI ID along with the service address and account number.

Does my ESI ID change if I switch providers?

No. The ESI ID belongs to the service delivery point. When you switch, only the REP of record attached to it changes. ESI IDs can change in rare cases, such as when one utility acquires another utility's territory.

Can I look up an ESI ID by address?

Yes. Oncor offers a public address lookup for its territory, your REP can confirm the number, and third-party tools draw on ERCOT's public ESI ID extract. Before you rely on a result, check that the suite or unit matches and that the status is Active.

Is ESID the same as ESIID?

Yes. ESI ID, ESID and ESIID are all spellings of Electric Service Identifier. ERCOT's extract files and Smart Meter Texas forms write it as ESIID.

Do I need my ESI ID to get a quote?

It helps, but you don't have to hunt for it separately. For an existing location, a recent bill is the complete input for a quote, and the ESI ID is printed on it. A new site with no bill can still be quoted from its address, square footage and type of business.

Does a new meter give me a new ESI ID?

Normally no. When the TDU exchanges a meter, the meter details recorded on the existing ESI ID are updated. A brand-new service delivery point, such as a new building, gets a new ESI ID.

What does it mean if my building has no ESI ID?

Usually that the meter is outside Texas retail choice, for example in Austin Energy, CPS Energy or a co-op territory that has not opted in, or that the utility has not extended service to the site yet. It can also mean your suite is submetered behind a landlord's master meter.