| Inscription | Country | Years | #Issued |
| UAR (value M) | Egypt | 1958-71 | |
| UAR(value P) | Syria | ||
| U.G. | Uganda | 1895 | 45 |
| Uganda | Uganda | 1896- | 600 |
| Ultramar | Cuba | 1870-79 | |
| Umm al Qiwain | Umm al Qiwain(exploitative) | 1964-73 | 950 |
| Union of Burma | Burma | 1948- | |
| Union of South Africa | South Africa | 1913-22 | 20 |
| United Arab Emirates | United Arab Emirates | 1971- | 250 |
| United Nations | U.N. (New York) | 1951- | 450 |
| Uruguay | Uruguay | 1956- | 1000 |
| Uzbekistan | Uzbekistan | 1992- |
If there are any missing inscription, tell me : marcosampaio@grupo.bfe.pt
