Look up a US or Canadian area code

Type an area code, a phone number or a state. Get the state or province, the main cities, the time zone and the overlay codes, and how many businesses 67Leads lists with that area code. Free, no account.

Area code 303: Denver, Colorado

Area code 303 covers Denver, Aurora, Boulder and Lakewood in Colorado. Time zone: Mountain (UTC-7, UTC-6 in daylight saving time). It shares its area with 720: overlay codes cover the same places, so local calls need all ten digits.

Area codesState or provinceMain citiesTime zone
303, 720ColoradoDenver, Aurora, Boulder, LakewoodMountain (UTC-7, UTC-6 in daylight saving time)

Other Colorado codes: all 3 areas in Colorado

67Leads lists 1,310 businesses with a 303 phone number, as of 8 Nov 2026: dentists 255, tree service companies 213, roofing contractors 143, electricians 113, plumbers 112, law firms 104.

Colorado: 4,065 businesses listed

Tree service companies in Colorado (830)Dentists in Colorado (468)Roofing contractors in Colorado (445)Plumbers in Colorado (386)HVAC contractors in Colorado (380)Med spas in Colorado (329)Law firms in Colorado (313)Electricians in Colorado (283)Cleaning companies in Colorado (246)Chiropractors in Colorado (168)Pest control companies in Colorado (118)

Lead lists for these cities

Law firms in Denver, CO (142)Dentists in Denver, CO (91)Roofing contractors in Denver, CO (75)Med spas in Denver, CO (68)Cleaning companies in Denver, CO (66)Chiropractors in Denver, CO (57)

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Area codes by state

369 area codes in 254 areas. Codes listed together in one area are overlays: they cover the same places.

StateArea codes
Alabama205, 251, 256, 334, 659, 938
Alaska907
Arizona480, 520, 602, 623, 928
Arkansas479, 501, 870
California209, 213, 279, 310, 323, 408, 415, 424, 442, 510, 530, 559, 562, 619, 626, 628, 650, 657, 661, 669, 707, 714, 747, 760, 805, 818, 820, 831, 858, 909, 916, 925, 949, 951
Colorado303, 719, 720, 970
Connecticut203, 475, 860, 959
Delaware302
District of Columbia202
Florida239, 305, 321, 352, 386, 407, 561, 689, 727, 754, 772, 786, 813, 850, 863, 904, 941, 954
Georgia229, 404, 470, 478, 678, 706, 762, 770, 912
Hawaii808
Idaho208, 986
Illinois217, 224, 309, 312, 331, 447, 464, 618, 630, 708, 730, 773, 779, 815, 847, 872
Indiana219, 260, 317, 463, 574, 765, 812, 930
Iowa319, 515, 563, 641, 712
Kansas316, 620, 785, 913
Kentucky270, 364, 502, 606, 859
Louisiana225, 318, 337, 504, 985
Maine207
Maryland240, 301, 410, 443, 667
Massachusetts339, 351, 413, 508, 617, 774, 781, 857, 978
Michigan231, 248, 269, 313, 517, 586, 616, 734, 810, 906, 947, 989
Minnesota218, 320, 507, 612, 651, 763, 952
Mississippi228, 601, 662, 769
Missouri314, 417, 573, 636, 660, 816
Montana406
Nebraska308, 402, 531
Nevada702, 725, 775
New Hampshire603
New Jersey201, 551, 609, 640, 732, 848, 856, 862, 908, 973
New Mexico505, 575
New York212, 315, 332, 347, 516, 518, 585, 607, 631, 646, 680, 716, 718, 838, 845, 914, 917, 929, 934
North Carolina252, 336, 704, 743, 828, 910, 919, 980, 984
North Dakota701
Ohio216, 220, 234, 326, 330, 380, 419, 440, 513, 567, 614, 740, 937
Oklahoma405, 539, 580, 918
Oregon458, 503, 541, 971
Pennsylvania215, 223, 267, 272, 412, 445, 484, 570, 610, 717, 724, 814, 878
Puerto Rico787, 939
Rhode Island401
South Carolina803, 839, 843, 854, 864
South Dakota605
Tennessee423, 615, 629, 731, 865, 901, 931
Texas210, 214, 254, 281, 325, 346, 361, 409, 430, 432, 469, 512, 682, 713, 737, 806, 817, 830, 832, 903, 915, 936, 940, 945, 956, 972, 979
Utah385, 435, 801
Vermont802
Virginia276, 434, 540, 571, 703, 757, 804
Washington206, 253, 360, 425, 509, 564
West Virginia304, 681
Wisconsin262, 414, 534, 608, 715, 920
Wyoming307

Area codes by Canadian province

ProvinceArea codes
Alberta403, 587, 780, 825
British Columbia236, 250, 604, 672, 778
Manitoba204, 431
New Brunswick428, 506
Newfoundland and Labrador709
Nova Scotia and Prince Edward Island782, 902
Ontario226, 249, 289, 343, 365, 416, 437, 519, 548, 613, 647, 705, 807, 905
Quebec418, 438, 450, 514, 579, 581, 819, 873
Saskatchewan306, 639
Yukon, Northwest Territories and Nunavut867

Where the table comes from

North American Numbering Plan assignments (NANPA), compiled for 67Leads; recently added overlays may be missing. An area code shows where a number was first assigned, not where its owner is today: mobile numbers move with people. The business counts are live from the 67Leads warehouse, by the area code of each listing's phone number.

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Questions

How do I find where an area code is?

Type the three digits, or a whole phone number, in the box above. You get the state or province, the main cities it covers, its time zone and any overlay codes.

What is an overlay area code?

A second code added to the same area when the first runs out of numbers. Both codes cover the same places, which is why local calls there need all ten digits.

Is 800 an area code?

No. 800, 833, 844, 855, 866, 877 and 888 are toll-free codes: the number can ring anywhere in the US or Canada.

Does an area code tell me a business's time zone?

Usually. A few areas cross a time zone line, such as 850 in the Florida panhandle or 915 in El Paso; the result names every zone an area spans.

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