| Abbreviation | Definition |
|---|---|
| MY7 | Malaysia |
| MZ | Mozambique |
| NA | Namibia |
| NALC | National Association of Letter Carriers |
| NAM | National Account Manager |
| NASS | National Air and Surface System |
| NB | New Brunswick |
| NBMS | National Bulk Mail System |
| NBS | National Budget System |
| NC | New Caledonia |
| NCD | Non-City Delivery office |
| NCED | National Center for Employee Development |
| NCOA | National Change of Address System |
| NCSC | National Customer Support Center |
| NDA | Next Day Air |
| NDCBU | Neighborhood Delivery and Collection Box Unit |
| NDF | Non-Deliverable Forward |
| NDF | Non-Deliverable, Forward |
| NDI | National Deliverability Index |
| NF | NewFoundland |