| 1 | NTN | NAC Aviation Business Centre (PTY) Ltd. d/b/a National Airlines | IATA: YJ, Callsign: Natchair, Designator YJ recalled by IATA | ZA | AVCODES |
| 2 | NTN | NAC Aviation Business Centre (PTY) Ltd. d/b/a National Airlines | Callsign: Natchair, Designator YJ recalled by IATA | ZA | AVCODES |
| 3 | NTNB | NORTON, B W MFG CO INC | | | SCAC3 |
| 4 | NTND | NTN TRUCKING LTD | | | SCAC4 |
| 5 | NTNH | NORTHSTAR TOURS OF NEW HAMPSHIRE | | | SCAC3 |
| 6 | NTNI | NINE ZERO ONE TWO- NINE SEVEN FIVE | | | SCAC4 |
| 7 | NTNL | NINE ZERO THREE SIX-FIVE TWO SIX TH | | | SCAC4 |
| 8 | NTNP | NATION TO NATION PREMIUM CEDAR | | | SCAC4 |
| 9 | NTNT | NEWTON TRANSPORTATION INC | | | SCAC3 |
| 10 | NTNU | NATIONAL CONTAINER NETWORK, INC. | | | PWRC |
| 11 | NTNU | National Container Network | | | RSRV |
| 12 | NTNU | NATIONAL CONTAINER NETWORK | | | SCAC3 |
