Significant events for area code 418
| Date |
Details |
| 1947 | One of the two original area codes for Quebec |
| 1957 | Area code 514 was split three ways with 514 remaining in the south, 819 covering the middle. The northwestern area (which had no telephone service at the time) transferred to 418 |
| 1958 | Area code 418 expanded to the Northwest Territories which then first received telephone service |
| 197? | Northern areas plus the Northwest Territories were moved to 819 |
| Quebec 418 overlays. |