| Abbreviation | Definition |
|---|---|
| HAC | Halloway Arms Company |
| HAC | Holloway Arms Company |
| HAC | Honourable Artillery Company |
| HAC | Horler And Company |
| HAC | Housing Assistance Corporation |
| HAC | Hughes Aircraft Company |
| HACB | Hiap Aik Construction Berhad |
| HACI | Honda Aircraft Company Inc |
| HACR | Heating, Air Conditioning, and Refrigeration |
| HAD | Hearing Aid Dealer |
| HADC | Hartford Area Development Corp |
| HADC | Hartford Area Development Corporation |
| HADC | Hough Area Development Corp |
| HAFI | High Aspirations Foundation Inc |
| HAFI | Homeless Assistance Fund Inc |
| HAHI | Help at Home Inc |
| HAHI | Home Account Holdings, Inc. |
| HAI | HAL America Inc |
| HAI | Hauling Anything Inc |
| HAI | Help Association Inc |