| Abbreviation | Definition |
|---|---|
| ISN | Insured Statistical Number |
| ISO | Independent Sales Organization |
| ISO | Industry Standard Operation |
| ISO | Insurance Service Organization |
| ISO | International Standards Organization |
| ISP | Innovative Service Program |
| ISP | inside screen porch |
| ISP | Intrinsically Safe for Process |
| ISR | Invoice Summary Register |
| ISS | Important Slam Shooter |
| ISS | Instrument Sales And Service |
| ISSAI | International Standards of Supreme Audit Institutions |
| IST | Integrated Service Team |
| ISTI | International Standard for Testing and Investigations |
| ITA | Individual Training Account |
| ITA | Industry Technical Agreement |
| ITAM | Integrated Training Area Management |
| ITAP | Information Technology Achievement Programme |
| ITAP | Information Technology Alignment Program |
| ITAS | Integrated Time and Attendance System |