| District of Ontario area codes: 905 | |
|---|---|
| Country | Canada |
| State/Province | Ontario |
| Major City | Richmond Hill |
| Time Zone | Eastern |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 905-304 | Ancaster, ON | Bell Canada | |
| 905-305 | Unionville, ON | Bell Canada | |
| 905-306 | Cooksville, ON | Bell Canada | |
| 905-307 | Unionville, ON | Rogers Communications Partnership (cable) | |
| 905-308 | Hamilton, ON | Bell Canada | |
| 905-309 | Grimsby, ON | Bell Canada | |
| 905-310 | Bell Canada | ||
| 905-312 | Hamilton, ON | Bell Canada | |
| 905-313 | Oak Ridges, ON | Bell Canada | |
| 905-314 | Hamilton, ON | Bell Canada | |
| 905-315 | Burlington, ON | Bell Canada | |
| 905-316 | Unionville, ON | Bell Canada | |
| 905-317 | Hamilton, ON | Bell Canada | |
| 905-318 | Hamilton, ON | Bell Canada | |
| 905-319 | Burlington, ON | Bell Canada | |
| 905-320 | Burlington, ON | Rogers Communications Partnership (wireless) | |
| 905-321 | Saint Catharines Thorold, ON | Rogers Communications Partnership (wireless) | |
| 905-322 | Saint Catharines Thorold, ON | Bell Canada | |
| 905-323 | Saint Catharines Thorold, ON | Bell Canada | |
| 905-324 | Saint Catharines Thorold, ON | Fido Solutions Inc. |
There are 770 prefixes, In the code area, the major cities are Stouffville, ON;Fisherville, ON;Richmond Hill, ON;. The major city is Stouffville.