| 9241 | Harness drivers | |
| 5139 | Harness equipment, wholesale | |
| 1911 | Harness leather, manufacturing | |
| 2893 | Harness parts, metal, manufacturing | |
| 9241 | Harness race tracks | |
| 5260 | Harness repair | |
| 5260 | Harness repair shops | |
| 1912 | Harnesses and harness parts, leather, manufacturing | |
| 1912 | Harnesses, dog, manufacturing | |
| 5139 | Harnesses, leather, wholesale | |
| 3692 | Harps and parts, manufacturing | |
| 3692 | Harpsichords, manufacturing | |
| 2921 | Harrows (e.g., disc, spring, tine), manufacturing | |
| 5150 | Harrows, ploughs and tillers, farm and garden, wholesale | |
| 1810 | Harvest hats, straw, manufacturing | |
| 2921 | Harvesting machinery and equipment, manufacturing | |
| 5150 | Harvesting machinery and equipment, wholesale | |
| 0140 | Harvesting service, agricultural crop and plant | |
| 2930 | Hassock fans, electric, manufacturing | |
| 1721 | Hassocks, textile material, not on wooden frame, manufacturing | |
| 3610 | Hassocks, upholstered on wood frames, manufacturing | |
| 5131 | Hat and cap material, wholesale | |
| 1810 | Hat bodies (e.g., fur-felt, straw, wool-felt), made from purchased fabric | |
| 1912 | Hat boxes (except paper or paperboard), manufacturing | |
| 9301 | Hat cleaning and blocking | |
| 1810 | Hat findings, made from purchased fabric | |
| 2926 | Hat making machinery, manufacturing | |
| 2029 | Hat racks, wood, manufacturing | |
| 0122 | Hatcheries, poultry | |
| 2893 | Hatchets, manufacturing | |
| 1810 | Hats (except fur, leather), made from purchased fabric | |
| 1820 | Hats and caps (except fur), cut and sewn from materials owned by others | |
| 1820 | Hats and caps, fur, cut and sewn from materials owned by others | |
| 5232 | Hats and caps, men's and boys', retail | |
| 5131 | Hats and caps, men's and boys', wholesale | |
| 5232 | Hats and caps, retail | |
| 1810 | Hats, cloth, made from purchased fabric | |
| 1820 | Hats, fur, manufacturing | |
| 1820 | Hats, fur, men's, manufacturing | |
| 1820 | Hats, fur, women's, manufacturing | |