| National Fuel Gas Supply Corporation | Owner/operator | Williamsville, NY | 34 | 33 |
| National Gas & Oil Cooperative | Owner/operator | Newark, OH | 1 | 1 |
| National Gas & Oil Corp | Owner/operator | Newark, OH | | 1 |
| National Grid LNG, L.P. | Owner/operator | | 1 | 1 |
| National Grid USA | Owner/operator | Syracuse, NY | | 1 |
| National Marine Fisheries Service | Owner/operator | | 1 | |
| National Oilwell Varco LP - Tulsa | Owner/operator | | | 1 |
| National Serv All | Owner/operator | FT Wayne, IN | | |
| Natnl Fuel Gas Corp | Owner/operator | | 1 | |
| Natural Gas Of Kentucky, Inc. | Owner/operator | Anchorage, KY | | 1 |
| Natural Gas Pipeline Company of America LLC | Owner/operator | Houston, TX | 59 | 13 |
| Natural Gas Processors Inc | Owner/operator | | | |
| Natural Resource Group, LLC | Third-party inspection | | 2 | |
| Natural Resources Worldwide LLC | Owner/operator | Dallas, TX | | 1 |
| Nautilius Pipeline Company, L.L.C. | Owner/operator | | 1 | |
| Nautilus Pipeline CO | Owner/operator | | 1 | |
| Navajo Nation Oil And Gas Company | Owner/operator | St. Michaels, AZ | | 1 |
| Navajo Tribal Utility Authority | Owner/operator | Fort Defiance, AZ | | 1 |
| Navarro Midstream Services, Llc. | Owner/operator | San Antonio, TX | | 2 |
| Navasota Odessa Energy Partners, L.p. | Owner/operator | | | |
| Navasota Wharton Energy Partners, LP | Owner/operator | | | |
| Navidad Resources LLC | Owner/operator | Tyler, TX | | 1 |
| Navigator Borger Express LLC | Owner/operator | Dallas, TX | | 1 |
| Navigator Energy Services, LLC | Owner/operator | | 2 | |
| Navigator PH Crossing LLC | Owner/operator | Dallas, TX | | 1 |
| Navigator Panhandle Holdco LLC | Owner/operator | Dallas, TX | | 1 |
| Navigator SMS Pipeline | Owner/operator | Dallas, TX | | 1 |
| Navitas MDSTR Midland Basin, LLC | Owner/operator | Houston, TX | | 2 |
| Navitas Midstream | Owner/operator | | 1 | |
| Navitas Midstream Midland Basin, LLC | Owner/operator | | | 2 |
| Navitas Pipeline Texas, LLC | Owner/operator | The Woodlands, TX | | 1 |
| Navitas Utility Coporation | Owner/operator | Eakly, OK | | 1 |
| Ne Ok Public Facilities Authority | Owner/operator | Tahlequah, OK | | 1 |
| Nebraska City Utilities | Owner/operator | Nebraska City, NE | | 1 |
| Nebraska Public Power Dist | Owner/operator | | | |
| Nebraska Public Power District | Owner/operator | Beatrice, NE | | 1 |
| Nec Operating, LLC | Owner/operator | | | 1 |
| Nei Arkansas Gathering Inc | Owner/operator | | | |
| Nemaha Gas Gathering LLC | Owner/operator | | | 1 |
| Neokc Pipeline | Owner/operator | Oklahoma City, OK | | 1 |
| Neptune LNG LLC | Owner/operator | Houston, TX | 1 | 1 |
| Nesson Gathering System, LLC | Owner/operator | Spring, TX | | 4 |
| Nesson Gathering Systems, LLC | Owner/operator | | | 1 |
| Net Mexico Pipeline Partners, LLC | Owner/operator | Houston, TX | 1 | 17 |
| Netco Pipeline LLC | Owner/operator | Austin, TX | | 2 |
| Neuhaus, V. F. Properties, Inc. | Owner/operator | | | 1 |
| Neumin Production Co. | Owner/operator | Point Comfort, TX | 1 | 4 |
| Nevada Gold Mines | Owner/operator | Elko, NV | | 1 |
| New Century Exploration | Owner/operator | Houston, TX | | 1 |
| New Dominion LLC | Owner/operator | Tulsa, OK | | 1 |