Richmond Hill City Area Code List
| Area Codes | Country | State | City | Time Zone | Operating |
|---|---|---|---|---|---|
| 289 | Canada | Ontario | Richmond Hill | Eastern | Details |
| 718 | US | New York - NY | Richmond Hill | Eastern | Details |
| 905 | Canada | Ontario | Richmond Hill | Eastern | Details |
| 912 | US | Georgia - GA | Richmond Hill | Eastern | Details |
| 929 | US | New York - NY | Richmond Hill | Eastern | Details |