| Abbreviation | Definition |
|---|---|
| GE | Georgia |
| GF | French Guiana |
| GH | Ghana |
| GI | Gibraltar |
| GL | Greenland |
| GM | Gambia |
| GMF | General Mail Facility |
| GMS | General Mail System |
| GN | Guinea |
| GP | Guadeloupe |
| GPL | Global Package Link |
| GPM | Global Priority Mail |
| GPMC | General Purpose Mail Container |
| GPO | General Post Office |
| GPO | General Post Office, United Kingdom |
| GQ | Equatorial Guinea |
| GS | S. Georgia and S. Sandwich Isls. |
| GT | Guatemala |
| GU | Guam |
| GW | Guinea-Bissau |