| Locality | Post Code |
|---|---|
| Ackley, Hardin | 50601 |
| Alden, Hardin | 50006 |
| Buckeye, Hardin | 50006 |
| Cleves, Hardin | 50601 |
| Eldora, Hardin | 50627 |
| Faulkner, Hardin | 50601 |
| Garden City, Hardin | 50102 |
| Gifford, Hardin | 50259 |
| Hubbard, Hardin | 50122 |
| Iowa Falls, Hardin | 50126 |
| Lawn Hill, Hardin | 50206 |
| Macy, Hardin | 50601 |
| New Providence, Hardin | 50206 |
| Owasa, Hardin | 50126 |
| Radcliffe, Hardin | 50230 |
| Robertson, Hardin | 50601 |
| Steamboat Rock, Hardin | 50672 |
| Union, Hardin | 50258 |
| Whitten, Hardin | 50269 |