| Impact Insurance Class | Academic & Science |
| Ipact Insulation Class | Academic & Science |
| Impact Isolation Class | Academic & Science |
| Institute of Chilean Engineers | Academic & Science |
| Instituto de Ingenieros de Chile | Academic & Science |
| Insurance Institute of Canada | Business |
| Institutional Investment Consulting | Business |
| International Immunology Corporation | Business |
| International Information Center | Business |
| Igorot International Consultation | Business |
| Intelligent Inspection Company | Business |
| Investing In Communities | Community |
| Islamic Information Center | Community |
| International Institute of Communications | Community |
| Internet Image Collector | Computing |
| Ibm Innovation Centers | Computing |
| Industrial Internet Consortium | Computing |
| Initiative in Innovative Computing | Computing |
| Inter Integrated Circuit | Computing |
| Intelligent Investment Chain | Cryptocurrency |
| International Islamic College | Educational Institute |
| Intermediate Image Carrier | Electronics |
| Idiots In Charge | General |
| Intercultural International Center | General |
| Integrated Imaging Center | General |
| International Indoor Championships | General |
| Independent International Consultants | General |
| Indiana Integrated Circuits | General |
| Idaho Industrial Commission | General |
| Individual Incentive Compatibility | General |
| Innovation Implementation and Coaching | General |
| Impact Insulation Class | General |
| Inter Item Constraint | General |
| Intuitive Insightful Criteria | General |
| Inmate Information Center | General |
| Intergovernmental Internship Cooperative | General |
| Item Identification Code | General |
| Identity Intelligence Center | General |
| International Innovation Corps | General |
| Industry Interface Cell | General |
| Industrial Interface Cell | General |
| If im correct | General |
| Interdependence Integration Co | General |
| Indiana Impreza Club | General |
| Indonesia Innova Community | General |
| Inspector-In-Charge | Governmental |
| Investigator in Charge | Governmental |
| Intercultural Institute of California | Governmental |
| Institute for Integrated Catalysis | Governmental |
| International Institute for Conservation | Governmental |
| The International Instructor Council | Governmental |
| Interdepartmental Intelligence Conference | Governmental |
| Internal Investigation Command | Governmental |
| Institution Identification Codes | Governmental |
| India International Centre | International |
| Indotronix International Corporation | International |
