| 15100.40.10 | Oamaru monumental or building stone |
| 01160.20 | Oats for grain |
| 48300.20.10 | Objective lenses |
| 48300.10.20 | Objective lenses for cameras or projectors |
| 93321.30 | Occasional child care services |
| 16120.35 | Ochres |
| 45100.90 | Office and accounting machinery parts and accessories n.e.c. |
| 42900.94 | Office articles |
| 42900.52.20 | Office equipment other than office furniture, sheet metal |
| 88231.00 | Office machinery manufacturing services |
| 45100.40 | Office machinery n.e.c. |
| 42900.52.10 | Office or desk equipment other than office furniture, base metal (excluding sheet metal), other |
| 45100.20 | Office type sheet fed printing machinery, accessories and parts |
| 53122.30 | Offices |
| 32100.12 | Offset plates of paper |
| 21800.10 | Oil-cake from the extraction of vegetable fats or oils |
| 43900.50 | Oil filters for internal combustion engines |
| 53200.55.10 | Oil industry constructions |
| 01490.20 | Oil poppies |
| 01490.90 | Oil seeds and oleaginous fruits n.e.c. |
| 22900.90 | Oils derived from milk |
| 21600.60 | Oils, animal, processed |
| 21600.60 | Oils, animal, refined |
| 21600.60 | Oils, vegetable, processed |
| 21600.60 | Oils, vegetable, refined |
| 01230.43 | Okra, fresh or chilled |
| 34200.40 | Oleum |
| 01316.56 | Olives, fresh or chilled |
| 84200.90 | On-line access services, other |
| 84300.90 | On-line information provision services, other |
| 85100.20 | On hired staff placement services except apprentice or trainee placements services |
| 53114.10 | One storey apartment not attached to a house |
| 53114.10 | One storey flat not attached to a house |
| 53113.10 | One storey row or terrace houses |
| 53113.10 | One storey semi-detached houses |
| 53113.10 | One storey townhouses |
| 53114.10 | One storey unit not attached to a house |
| 01230.01.40 | Onions, brown, chilled |
| 01230.01.40 | Onions, brown, fresh |
| 01230.01.40 | Onions, white, chilled |
| 01230.01.40 | Onions, white, fresh |
| 35100.50 | Opacifiers for ceramics |
| 35100.50 | Opacifiers for enamelling |
| 35100.50 | Opacifiers for glass |
| 16310.30 | Opals |
| 96910.10 | Operation services of preserved railways |
| 48100.30 | Ophthalmic instruments and appliances |
| 93191.70 | Optical dispensing services |
| 48300.20.20 | Optical fibres for purposes other than computing or telephony |
| 48300.20.10 | Optical filters |
| 37100.90 | Optical glassware |
| 88234.00 | Optical instrument manufacturing services |
| 48300.20.90 | Optical instruments parts and accessories, other |
| 48300.20.90 | Optical instruments, other |
| 93191.60 | Optometry services (excluding optical dispensing) |
| 93123.20 | Oral surgery services |
| 01313.40 | Oranges, fresh |
| 01500.20.90 | Orchard trees excluding apples and pears |
| 01230.44 | Oregano |
| 34100.50 | Organic chemicals n.e.c. |
| 34100.30.55 | Organic derivatives of hydrazine |
| 34100.30.55 | Organic derivatives of hydroxylamine |
| 34100.40 | Organo-inorganic compounds |
| 38900.42 | Original engravings, |
| 38900.42 | Original lithographs |
| 38900.42 | Original prints |
| 38900.45 | Original sculptures and statuary, in any material |
| 37200.20 | Ornamental articles n.e.c., ceramic |
| 37100.90 | Ornamental glass |
| 37500.40 | Ornamental goods, concrete |
| 42900.36 | Ornaments n.e.c., metal (other than precious) |
| 93123.90 | Orthodontic services |
| 93191.20 | Osteopathic services |
| 02129.60 | Ostriches, live |
| 38170.10.10 | Ottomans |
| 53200.45.90 | Outdoor recreation facilities other than buildings, other |
| 53200.45.90 | Outdoor sports facilities other than buildings, other |
| 93110.30 | Outpatient hospital services |
| 93325.70 | Outreach services |
| 35322.20 | Oven cleaners |
| 44800.12 | Ovens, domestic gas, solid fuel, oil or spirit fired |
| 44800.08 | Ovens, domestic, electric |
| 91113.00 | Over-all economic public services |
| 28200.30 | Overalls, boys |
| 28200.48 | Overalls, girls |
| 28200.30 | Overalls, men |
| 28200.72 | Overalls, plastic |
| 28200.72 | Overalls, rubber |
| 28200.72 | Overalls, waterproof |
| 28200.48 | Overalls, women's |
| 34200.50 | Oxygen |
| 34100.30.25 | Oxygen- function amino compounds |
| 04200.10 | Oysters, live, fresh or chilled |
| 48100.25 | Ozone therapy apparatus |