Area Code 312 is located in the state of Illinois.
The Illinois`s major city is Chicago
The state of Illinois is in Central timezone.
More important cities in Illinois:
Chicago, IL;
Prefixes within the 312 Area Code what we have in our database.
| Prefix | Primary City | County | Usage |
| (312) 768 | Chicago, IL | Cook | Landline |
| (312) 769 | Chicago, IL | Cook | Cell Number |
| (312) 770 | Chicago, IL | Cook | Landline |
| (312) 771 | Chicago, IL | Cook | Cell Number |
| (312) 772 | Chicago, IL | Not filled | Unknown |
| (312) 775 | Chicago, IL | Cook | Landline |
| (312) 777 | Chicago, IL | Cook | Landline |
| (312) 780 | Chicago, IL | Cook | Landline |
| (312) 781 | Chicago, IL | Cook | Landline |
| (312) 782 | Chicago, IL | Cook | Landline |
| (312) 784 | Chicago, IL | Not filled | Unknown |
| (312) 785 | Not filled | Not filled | Unknown |
| (312) 786 | Chicago, IL | Cook | Landline |
| (312) 787 | Chicago, IL | Cook | Landline |
| (312) 788 | Chicago, IL | Cook | Landline |
| (312) 789 | Chicago, IL | Cook | Landline |
| (312) 790 | Chicago, IL | Cook | Cell Number |
| (312) 791 | Chicago, IL | Cook | Landline |
| (312) 793 | Chicago, IL | Cook | Landline |
| (312) 794 | Chicago, IL | Cook | Landline |
| (312) 795 | Chicago, IL | Cook | Landline |
| (312) 796 | Not filled | Cook | Landline |
| (312) 797 | Chicago, IL | Cook | Landline |
| (312) 798 | Chicago, IL | Cook | Landline |
| (312) 799 | Chicago, IL | Cook | Landline |
| (312) 801 | Not filled | Cook | Cell Number |
| (312) 802 | Chicago, IL | Cook | Cell Number |
| (312) 803 | Chicago, IL | Cook | Landline |
| (312) 804 | Chicago, IL | Cook | Cell Number |
| (312) 805 | Chicago, IL | Cook | Cell Number |
| (312) 806 | Chicago, IL | Cook | Cell Number |
| (312) 807 | Chicago, IL | Cook | Landline |
| (312) 808 | Chicago, IL | Cook | Landline |
| (312) 810 | Chicago, IL | Cook | Cell Number |
| (312) 812 | Chicago, IL | Cook | Cell Number |
| (312) 813 | Chicago, IL | Cook | Cell Number |
| (312) 814 | Chicago, IL | Cook | Landline |
| (312) 816 | Hinsdale, IL | Du Page | Cell Number |
| (312) 817 | Chicago, IL | Cook | Landline |
| (312) 818 | Not filled | Cook | Cell Number |
| (312) 819 | Chicago, IL | Cook | Landline |
| (312) 820 | Chicago, IL | Cook | Cell Number |
| (312) 821 | Chicago, IL | Cook | Landline |
| (312) 822 | Chicago, IL | Cook | Landline |
| (312) 823 | Chicago, IL | Cook | Landline |
| (312) 824 | Not filled | Cook | Cell Number |
| (312) 825 | Not filled | Cook | Cell Number |
| (312) 826 | Not filled | Cook | Cell Number |
| (312) 827 | Chicago, IL | Cook | Landline |
| (312) 828 | Chicago, IL | Cook | Landline |
| (312) 829 | Chicago, IL | Cook | Landline |
| (312) 830 | Chicago, IL | Cook | Cell Number |
| (312) 831 | Chicago, IL | Cook | Landline |
| (312) 832 | Chicago, IL | Cook | Landline |
| (312) 833 | Chicago, IL | Cook | Cell Number |
| (312) 834 | Chicago, IL | Cook | Landline |
| (312) 835 | Chicago, IL | Cook | Cell Number |
| (312) 836 | Chicago, IL | Cook | Landline |
| (312) 837 | Chicago, IL | Cook | Cell Number |
| (312) 839 | Chicago, IL | Cook | Cell Number |
| (312) 840 | Chicago, IL | Cook | Landline |
| (312) 841 | Chicago, IL | Cook | Cell Number |
| (312) 842 | Chicago, IL | Cook | Landline |
| (312) 844 | Hinsdale, IL | Du Page | Cell Number |
| (312) 845 | Chicago, IL | Cook | Landline |
| (312) 846 | Chicago, IL | Cook | Landline |
| (312) 848 | Chicago, IL | Cook | Cell Number |
| (312) 849 | Chicago, IL | Cook | Landline |
| (312) 850 | Chicago, IL | Cook | Landline |
| (312) 851 | Chicago, IL | Cook | Cell Number |
| (312) 852 | Chicago, IL | Cook | Cell Number |
| (312) 853 | Chicago, IL | Cook | Landline |
| (312) 854 | Chicago, IL | Cook | Landline |
| (312) 855 | Chicago, IL | Cook | Landline |
| (312) 856 | Chicago, IL | Cook | Landline |
| (312) 857 | Chicago, IL | Cook | Landline |
| (312) 858 | Not filled | Not filled | Unknown |
| (312) 859 | Chicago, IL | Cook | Cell Number |
| (312) 860 | Chicago, IL | Cook | Cell Number |
| (312) 861 | Chicago, IL | Cook | Landline |
| (312) 862 | Chicago, IL | Cook | Landline |
| (312) 863 | Chicago, IL | Cook | Landline |
| (312) 864 | Chicago, IL | Cook | Landline |
| (312) 865 | Wheeling, IL | Cook | Cell Number |
| (312) 867 | Chicago, IL | Cook | Landline |
| (312) 869 | Chicago, IL | Cook | Landline |
| (312) 870 | Chicago, IL | Cook | Landline |
| (312) 873 | Chicago, IL | Cook | Landline |
| (312) 875 | Chicago, IL | Cook | Landline |
| (312) 876 | Chicago, IL | Cook | Landline |
| (312) 877 | Not filled | Cook | Cell Number |
| (312) 878 | Chicago, IL | Not filled | Unknown |
| (312) 879 | Chicago, IL | Cook | Landline |
| (312) 880 | Chicago, IL | Cook | Landline |
| (312) 881 | Chicago, IL | Cook | Landline |
| (312) 882 | Chicago, IL | Cook | Cell Number |
| (312) 884 | Chicago, IL | Cook | Landline |
| (312) 886 | Chicago, IL | Cook | Landline |
| (312) 887 | Chicago, IL | Cook | Landline |
| (312) 888 | Chicago, IL | Not filled | Unknown |
We have 695 Prefixes in our database.