| 83633 | Internet advertising space, sale of, directly by web publishers | |
| 84210 | Internet backbone services | |
| 84290 | Internet conferencing services | |
| 84290 | Internet fax services | |
| 84290 | Internet integrated messaging services | |
| 84300 | Internet publishing services | |
| 84290 | Internet telephony services | |
| 84210 | Internet traffic transport services | |
| 93122 | Interpretation of electrocardiograms | |
| 93122 | Interpretation of endoscopies | |
| 93122 | Interpretation of x-ray photographs | |
| 91270 | Interpretation services, legal | |
| 83910 | Interpretation services, oral | |
| 44914 | Intertype machines for setting and founding lines of type | |
| 64314 | Interurban airport limousine services | |
| 64313 | Interurban passenger transportation by bus, scheduled | |
| 64313 | Interurban passenger transportation by tramway, scheduled | |
| 64313 | Interurban passenger transportation by trolley, scheduled | |
| 64211 | Interurban passenger transportation provided by railway | |
| 64211 | Interurban railway transport services of passengers | |
| 64313 | Interurban scheduled road transport services of passengers | |
| 64314 | Interurban special-purpose passenger transportation by bus, scheduled | |
| 64314 | Interurban special-purpose passenger transportation by tramway, scheduled | |
| 64314 | Interurban special-purpose passenger transportation by trolley, scheduled | |
| 64314 | Interurban special-purpose scheduled road transport services of passengers | |
| 39110 | Intestines, animal (excl. of fish), whether or cut up or dried, whether or not edible | |
| 23220 | Inulin | |
| 73330 | Inventions, patents, licensing services for the right to use | |
| 83119 | Inventory mangement and control, consulting services concerning | |
| 34170 | Invertase | |
| 46122 | Inverters, electric | |
| 71620 | Investigation of insurance claims | |
| 84420 | Investigation of news for audio-visual media | |
| 84410 | Investigation of news for printed media | |
| 83700 | Investigation of public opinion regarding economic issues | |
| 83700 | Investigation of public opinion regarding political issues | |
| 83700 | Investigation of public opinion regarding social issues | |
| 85112 | Investigation of references by employment agencies | |
| 85111 | Investigation of references by executive search services | |
| 91112 | Investigation of tax violations | |