| 800 | toll-free; (see also 811, 822, 833, 844, 855, 866, 877, 888) |
| 801 | Utah (Salt Lake, Utah, Davis, Weber and Morgan counties, will overlay with 385 beginning mid-2008) |
| 802 | Vermont (all) |
| 803 | South Carolina (Columbia, Rock Hill, Sumter, Aiken and central South Carolina) |
| 804 | Virginia (Richmond, Petersburg, West Point, Chester; east central Virginia, Northern Neck, and Middle Peninsula) |
| 805 | California (San Luis Obispo, Santa Barbara, Isla Vista, Ventura, Santa Paula; southwest central coastal California) |
| 806 | Texas (Amarillo, Lubbock, Canadian, Perryton, Shamrock, Dalhart and Texas Panhandle) |
| 807 | Ontario (Northwestern Ontario: Thunder Bay, Kenora, Dryden, Greenstone) |
| 808 | Hawaii (all) |
| 809 | Today only covers the Dominican Republic, and is overlayed with 829. 809 was split into several area codes in the mid-1990s; the code previously covered all the Caribbean. |
| 810 | Michigan (Port Huron, Flint, Lapeer, and Michigan "Thumb", (originally split from 313 and included areas that later became 248 and 586) |
| 811 | Mobile customer service on some North American cellular carriers, also used as a 9-1-1 like emergency number to handle distress calls in much of Jamaica. |
| 812 | Indiana (Southern Indiana, including Bloomington, Evansville, Jeffersonville, New Albany, and Terre Haute). |
| 813 | Florida (all of Hillsborough County, including Tampa, Temple Terrace, and Plant City; inland areas of Pasco County, and Oldsmar) |
| 814 | Pennsylvania (Morrisdale, Erie, Warren, State College, Altoona, Johnstown, Meyersdale, Johnsonburg, St. Marys, Ridgway, DuBois, Emporium, and central and northwestern Pennsylvania) |
| 815 | Illinois (La Salle, De Kalb, Rockford, Freeport and northern Illinois including parts of the Chicago area such as Joliet, Plainfield and Crystal Lake, and is overlaid by 779) |
| 816 | Missouri (Kansas City, St Joseph, Independence, Harrisonville and west central Missouri) |
| 817 | Texas (Fort Worth, Arlington, Grandview, Weatherford, Rhome, overlays with 682) |
| 818 | California (Glendale, San Fernando, Burbank and northern Los Angeles suburbs) |
| 819 | Quebec (Abitibi-Temiscamingue, Mauricie, Outaouais and Estrie) |
| 822 | reserved for future toll-free expansion (see also 800, 833, 844, 855, 866, 877, 888) |
| 825 | reserved for future usage in Alberta, Canada. |
| 828 | North Carolina (Asheville, Brevard, Morganton, Murphy and western North Carolina) |
| 829 | the Dominican Republic (overlays with 809) |
| 830 | Texas (Del Rio, Uvalde, New Braunfels, Kerrville, Eagle Pass and southwest Texas) |
| 831 | California (Salinas, Hollister, Monterey, Santa Cruz and central western coastal California) |
| 832 | Texas (Houston area, overlays with 281 and 713) |
| 833 | reserved for future toll-free expansion (see also 800, 822, 844, 855, 866, 877, 888) |
| 835 | Pennsylvania (Reading, Allentown, and southeastern Pennsylvania, overlays with 484 and 610) |
| 843 | South Carolina (Florence, Myrtle Beach, Charleston, Isle of Palms, Hilton Head Island and eastern South Carolina) |
| 844 | reserved for future toll-free expansion (see also 800, 822, 833, 855, 866, 877, 888) |
| 845 | New York (Rockland, Poughkeepsie, Middletown, West Point, Newburgh and southeastern New York) |
| 847 | Illinois (Arlington Heights, Buffalo Grove, Wauconda, Waukegan, Des Plaines, northwest Chicago suburbs and northeastern Illinois, and is overlaid by 224) |
| 848 | New Jersey (New Brunswick, Neptune, Lakewood, and east central New Jersey, overlays with 732) |
| 850 | Florida (Pensacola, Tallahassee, Panama City and the Florida panhandle) |
| 855 | reserved for future toll-free expansion (see also 800, 822, 833, 844, 866, 877, 888) |
| 856 | New Jersey (Vineland, Cherry Hill, Camden, Millville, and southwestern New Jersey) |
| 857 | Massachusetts (Boston, Cambridge, east central Massachusetts and close-in Boston suburbs, overlays with 617) |
| 858 | California (Del Mar, La Jolla and other inner northern San Diego suburbs, northern half of city of San Diego) |
| 859 | Kentucky (Lexington, Richmond, Danville, Covington, Florence, Mount Sterling and north central Kentucky) |
| 860 | Connecticut (Bristol, Hartford, Norwich and northern and eastern Connecticut) |
| 862 | New Jersey (portions of Bergen, Essex, Morris, Passaic and Sussex counties in northern New Jersey) |
| 863 | Florida (Lakeland, Avon Park, Clewiston, Bartow, Sebring, Winter Haven and south central Florida) |
| 864 | South Carolina (Greenville, Spartanburg, Anderson and Upstate South Carolina) |
| 865 | Tennessee (Knoxville, Gatlinburg, Newport, Jefferson City, Oak Ridge, Rockwood and central East Tennessee), split from 423 in 1999. 865 one of many vanity area codes, is reference as 'VOL' representing Tennessee as the volunteer state. |
| 866 | toll-free (see also 800, 822, 833, 844, 855, 877, 888) |
| 867 | Yukon, Northwest Territories and Nunavut |
| 868 | Trinidad and Tobago, split from 809. (all) |
| 869 | Saint Kitts and Nevis, split from 809. (all) |
| 870 | Arkansas (Texarkana, Mountain Home, Pine Bluff and southern, eastern and northeastern Arkansas) |
| 872 | Illinois This Area code is scheduled to provide numbering relief to Area code 312 but no date has been assigned for this to go into effect. |
| 876 | Jamaica, split from 809. (all) |
| 877 | toll-free (see also 800, 822, 833, 844, 855, 866, 888) |
| 878 | Pennsylvania (Pittsburgh, New Castle, and southwestern Pennsylvania, overlays with 412 and 724) |
| 888 | toll-free (see also 800, 822, 833, 844, 855, 866, 877) |
