| Acronym | Definition |
|---|
| ECI | Early Childhood Intervention |
| ECI | Employment Cost Index |
| ECI | Election Commission(er) of India |
| ECI | Environmental Change Institute (Oxford University Centre for the Environment, UK) |
| ECI | Enterprise Content Integration |
| ECI | Effectively Connected Income (US IRS) |
| ECI | External Call Interface |
| ECI | European Coaching Institute (UK) |
| ECI | Extension Course Institute |
| ECI | Electronic Commerce Indicator (online transaction security) |
| ECI | Earth Centered Inertial |
| ECI | Eddy Current Inspection |
| ECI | Export Credit Insurance |
| ECI | Export Controlled Information |
| ECI | Extended Custodial Inventory |
| ECI | Edu-Culture International (Berkeley, CA) |
| ECI | Eldorado Computing, Inc. (Phoenix, Arizona) |
| ECI | Eastwood Collegiate Institute (Ontario, Canada) |
| ECI | Empty Chamber Indicator (firearms) |
| ECI | Egg Clearinghouse, Inc. |
| ECI | Enrollment for Core Infrastructure (Microsoft) |
| ECI | Effective Compensation, Incorporated |
| ECI | Enquiry of Commercial Interest |
| ECI | Engineering Change Instruction |
| ECI | Environmental Condition Indicator |
| ECI | Educational Curriculum & Instruction |
| ECI | Eloquence Command Interface (Eloquent Technology, Inc.) |
| ECI | Electronics Corporation of Israel |
| ECI | Employment Consultants Institute |
| ECI | Enhanced Cardiology Inc. |
| eCI | eCommerce Integrator |
| ECI | Error Cause Identification |
| ECI | Electronic Conversion Interface |
| ECI | Eco Computer, Incorporated |
| ECI | Electioneering Communication Individual |
| ECI | Experimental Control Interface |
| ECI | Expected Cost of Inspection |
| ECI | Electronic Communications Incorporated (later E-Systems) |
| ECI | Emerald Computers Inc. (Arizona) |
| ECI | Equipment and Inventory Control |
| ECI | Equipment Certification Instruction |
| ECI | Equipment Condition Inspection |
| ECI | Expert Consultants, International |
| ECI | Extract Criteria Information |
| ECI | Error Capturing Instruction |
| ECI | Extended Company Information |
| ECI | Educational Concepts International of Afghanistan |
| ECI | Earth Center Inertial Coordinates |
| ECI | European Construction Institute (est. 1990) |
| ECI | Early Contractor Involvement |
| ECi | Engine Components, Inc. (aviation) |
| ECI | El Corte Ingles (Spanish: The English Court; retailer) |
| ECI | Electronic Commerce on the Internet |
| ECI | Essence Communication Inc. (New York, NY) |
| ECI | Emergency Contact Information (various schools) |
| ECI | Enhanced Cartridge Interface (Atari computers) |
| ECI | Energy Control, Inc. (New Mexico) |