An “Electric Service Identifier” ID number that identifies your electric service location. This is pronounced "easy I.D." It's unique to the Texas electricity market.

In the state of Texas, an ESI ID is a 17 or 22-digit number used in the deregulated market to identify a unique point of electric service delivery to a premise (your home or business).

Each point of delivery receiving electricity (for example, a home, a business or a streetlight) is given a unique ESI number, often called the "Easy ID number." It's a 17- or 22-digit n [..]

The basic identifier assigned to each Service Delivery Point used in the registration and settlement systems managed by ERCOT or another Independent Organization.