| Locality | Post Code |
|---|---|
| Almonte, Lanark | K0A |
| Balderson, Lanark | K0G 1A0 |
| Carleton Place, Lanark | K7C |
| Clayton, Lanark | K0A 1P0 |
| Lanark, Lanark | K0G |
| Maberly, Lanark | K0H |
| McDonalds Corners, Lanark | K0G 1M0 |
| Pakenham, Lanark | K0A |
| Perth, Lanark | K7H |
| Rideau Ferry, Lanark | K0G 1W0 |
| Smiths Falls, Lanark | K7A |