| 3825 | Addressing machine manufacturing | |
| 3825 | Addressing plate and stencil manufacturing | |
| 8329 | Addressograph service | |
| 3529 | Adhesive paste manufacturing | |
| 3851 | Adhesive plaster, medicated, manufacturing | |
| 3851 | Adhesive tape, medicated, manufacturing | |
| 3420 | Advertisement typesetting | |
| 8325 | Advertising agency | |
| 8325 | Advertising copy writer, own account | |
| 3909 | Advertising curtain manufacturing | |
| 3909 | Advertising display manufacturing | |
| 3909 | Advertising novelty manufacturing | |
| 3909 | Advertising poster, excluding lithographed, manufacturing | |
| 3420 | Advertising poster, lithographed, manufacturing | |
| 8325 | Advertising sample distributing service | |
| 8321 | Advocate, own account | |
| 3811 | Adze manufacturing | |
| 3134 | Aerated water manufacturing | |
| 9592 | Aerial photography | |
| 7132 | Aerodrome operation | |
| 5000 | Aeroplane hangar construction | |
| 3845 | Aeroplane manufacturing | |
| 3522 | Agar-agar manufacturing | |
| 6100 | Agent, commission | |
| 6100 | Agent, commodity | |
| 6100 | Agent, manufacturers' | |
| 6200 | Agent, news | |
| 6100 | Agent, purchasing | |
| 8329 | Agricultural fair operation | |
| 3822 | Agricultural implement, except hand tools, manufacturing | |
| 3512 | Agricultural insecticide manufacturing | |
| 8102 | Agricultural loan institution | |
| 8330 | Agricultural machinery rental service without drivers | |
| 3822 | Agricultural plough manufacturing | |
| 3822 | Agricultural tractor manufacturing | |
| 3842 | Air brake for locomotive manufacturing | |
| 3842 | Air brake, pneumatic, for railways, manufacturing | |
| 3829 | Air compressor manufacturing | |
| 3813 | Air duct, sheet metal, manufacturing | |
| 3829 | Air exhaust and moving equipment manufacturing | |