Sheets of Tonga - Niuafo'ou, 1998
| Issuer | Date | Desc | State | ||
| - |  |
Niuafo'ou | 5/15/1998 | empty sheet (#60428) | incomplete |
| - | no image | Niuafo'ou | 5/29/1998 | empty sheet (#60429) | incomplete |
| - | no image | Niuafo'ou | 7/23/1998 | empty sheet (#60430) | incomplete |
| - | no image | Niuafo'ou | 9/23/1998 | empty sheet (#60431) | incomplete |