| 100% | QTS | 3 | Units equal to 40 fl. oz. in the UK, but only equal to 32 fl. oz. in the US |
| 36% | THATCHER | 8 | The only person to be UK PM in the 1980s |
| 34% | ABMHO | 5 | Unit of electrical conductance in the emu-cgs system, equal to 109 siemens |
| 34% | ZOOS | 4 | Only places to find anteaters in the U.S. |
| 33% | FHM | 3 | Men's magazine started in 1985 in the UK and reduced to a web only edition in 2015 |
| 32% | OAHU | 4 | Island home to the only royal palace in the U.S. |
| 32% | TONS | 4 | Heavy weights that are usually short in the US, but long in the UK |
| 32% | GARTH | 5 | Brooks, the only artist to release 9 diamond albums in the US |
| 31% | CALI | 4 | Only place in the U.S. to host both the Summer and Winter Olympics, informally |
| 31% | OAHU | 4 | Hawaiian island that's home to the only royal palace in the US |
| 31% | SPARTA | 6 | City name that occurs 19 times across the US, but oddly, only twice in Greece |
| 30% | PUERTORICO | 10 | Home to El Yunque, the only tropical rain forest in the U.S. national forest system |
| 30% | MIRREN | 6 | Only person to have won the Triple Crown of Acting in both the U.S. and the U.K. |
| 29% | ADDER | 5 | The only venomous snake in the UK |
| 29% | ORR | 3 | Only defenseman to lead the NHL in points |
| 29% | COOKIE | 6 | "Biscuit" in the UK, "__" in the US |
| 29% | THERESAMAY | 10 | Head of the only government in U.K. history to be found in contempt of Parliament |
| 28% | ASLAN | 5 | Only character to appear in all of the Narnia chronicles |
| 28% | CHECKERS | 8 | In the UK the game is called draughts, in the US _ |
| 28% | SEVENTEEN | 9 | Legal age for learning to drive in the UK |
| 28% | HALLOFFAME | 10 | This dedication to US Space Walking astronauts and equipment contractors is by the Indian R. in Titusville, FL. |
| 28% | OPOSSUM | 7 | Only marsupial found in the U.S. |
| 28% | CASPERRUUD | 10 | Norwegian tennis player who was runner-up to 32-Across in the men's singles championship at the 2022 US Open (2 wds.) |
| 28% | VETERANSDAY | 11 | US equivalent of Remembrance Day in the UK held on November 11 |
| 28% | NEPTUNE | 7 | Only planet in the solar system not visible to the naked eye |
| 27% | TERAOHM | 7 | Resistance unit equal to one trillion of the basic units |
| 27% | PFIZER | 6 | First COVID-19 vaccine to be approved in the UK |
| 27% | JOHNDOE | 7 | In the US, name given to an unidentified male body |
| 27% | TAHOE | 5 | Lake ___ (home to many ski resorts in the western US) |
| 27% | IOLANI | 6 | The only royal palace in the U.S. |