What is an ESID? Your Texas electric service ID, explained
An ESID (Electric Service Identifier, also written ESI ID) is the unique number — usually 17 to 22 digits — that identifies a single point of electric delivery in the ERCOT market. It isn't your meter number, it doesn't change when you switch providers, and it's the first thing you need for an accurate quote.
The number that identifies your power, not your provider
Every premise that takes electric service in the deregulated parts of the ERCOT market has one permanent identifier: the ESID, or Electric Service Identifier (you'll also see it written ESI ID). It's a long number — usually 17 to 22 digits — assigned by your local Transmission and Distribution Service Provider (TDSP) and registered with ERCOT when service to the location is first established.
Think of it as the street address of your electricity. REPs come and go, meters get swapped, businesses move in and out — the ESID stays with the service point. The leading digits identify which TDSP's territory the premise sits in.
Where to find it on your bill
Look on the first or second page of your electricity bill, usually near the service address or in the account-summary block, labeled ESI ID, ESID, or occasionally "Electric Service Identifier." It's the longest number on the page. If you genuinely can't find it, your REP or your TDSP can give it to you from the service address — or you can look it up yourself (more on that below).
ESID vs. meter number: not the same thing
The two get confused constantly, and the distinction matters:
- The meter number identifies a physical device — the box on the wall. Meters get replaced, upgraded and re-certified, and when that happens the meter number changes.
- The ESID identifies the service point — the delivery location in ERCOT's market systems. It survives meter swaps, provider switches and changes of tenant.
When a supplier asks for "your meter details" to produce a quote, what they almost always need is the ESID. Usage history, the TDSP rate class, and the switch itself are all keyed to it.
Why the ESID matters when you switch
Four practical reasons to have your ESIDs at hand before you go to market:
- Accurate quotes. With an ESID, a supplier or consultant can pull the premise's actual historical usage profile rather than pricing off an estimate. Better data, sharper price.
- No wrong-premise switches. Service addresses are ambiguous — suites, units, multiple meters on one site. The ESID is exact. Enrollments keyed to the right ESID don't accidentally switch the wrong location.
- Multi-site portfolios. If you operate ten or two hundred locations, the ESID list is your portfolio. Aggregated procurement, staggered contract end dates and site-level bill auditing all start from a clean ESID inventory.
- Move-ins and move-outs. When you take over or vacate a premise, the ESID is how service is started, stopped and transferred without billing gaps or overlaps.
Look up any Texas ESID
You don't need to wait for a bill. UPG's free ESID lookup tool lets you find the ESID for any Texas service address — useful when you're scoping a new site, assembling a portfolio list, or checking what's actually registered at a location before a switch.
Bottom line
The ESID is the one identifier in the Texas retail market that never changes hands: not your provider, not your meter, but the service point itself. Keep a current list of yours — and for anything more than a single site, treat that list as the foundation of every procurement, audit and renewal conversation you'll have.
What is an ESID? Your Texas electric service ID, explained — quick questions
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