| Abbreviation | Definition |
|---|---|
| ITMPSF | Information Technology Management for Credit Unions |
| ITU | Indian Telecom Union |
| ITU | Institute of Telephony Union |
| ITU | International Telecomunications Union |
| ITU | International Typographical Union |
| ITUC | International Trade Union Confederation |
| ITUK | Independent Trade Unions of Kosovo |
| ITUT | International Telecommunication Union - Telecommunication Standardization Sector (usually seen as IT |
| IUA | International Union of Architects |
| IUAA | Iraqi Union of Accountants and Auditors |
| IUAI | Internation Union of Aerospace Insurers |
| IUAI | International Union of Aerospace Insurers |
| IUAI | International Union of Aviation Insurers |
| IUAM | International Union of Advanced Materials |
| IUB | Illini Union Board |
| IUB | International Union of Biochem |
| IUBAC | International Union of Bricklayers & Allied Craftsmen |
| IUCB | International Union Of Canine Breeders |
| IUCC | International Union for Counteraction of Criminality |
| IUCF | International Union Of Cossacks Forces |