| General Information about Area Code 603 | |
|---|---|
| Country | United States |
| State / Province / Territory | New Hampshire |
| Major City | Manchester |
| Time Zone | Eastern (UTC-05:00) |
| Prefix | Primary City | County | Phone Type |
|---|---|---|---|
| 603-533 | Merrimack | Hillsborough | Wireless |
| 603-440 | Merrimack | Hillsborough | Landline |
| 603-200 | Newmarket | Rockingham | Landline |
| 603-618 | Warren | Grafton | Landline |
| 603-628 | Manchester | Hillsborough | Landline |
| 603-647 | Manchester | Hillsborough | Landline |
| 603-552 | Manchester | Hillsborough | Landline |
| 603-745 | North Woodstock | Grafton | Landline |
| 603-953 | Dover | Strafford | Landline |
| 603-939 | North Conway | Carroll | Landline |
| 603-269 | Pittsfield | Merrimack | Landline |
| 603-633 | Manchester | Hillsborough | Landline |
| 603-751 | Nashua | Hillsborough | Landline |
| 603-214 | Errol | Coos | Landline |
| 603-668 | Manchester | Hillsborough | Landline |
| 603-447 | Conway | Carroll | Landline |
| 603-331 | Colebrook | Coos | Landline |
| 603-329 | Hampstead | Rockingham | Landline |
| 603-481 | Manchester | Hillsborough | Wireless |
| 603-313 | Keene | Cheshire | Wireless |