All assignees
800 prefixes in 203 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 203-800 | NEW HAVEN | 6624 | 2011-03-10 | Yes |
| 203-801 | NEW CANAAN | 9147 | — | Yes |
| 203-802 | WATERBURY | 5562 | 2008-10-03 | Yes |
| 203-803 | NORWALK | 6388 | — | Yes |
| 203-804 | NEW HAVEN | 4036 | — | — |
| 203-805 | WATERBURY | 7143 | — | Yes |
| 203-806 | CHESHIRE | 7143 | — | Yes |
| 203-807 | NORWALK | 4036 | 2001-01-30 | Yes |
| 203-808 | WATERBURY | 6624 | 2002-05-30 | Yes |
| 203-809 | NEW HAVEN | 6624 | 2002-11-04 | Yes |
| 203-810 | NORWALK | 4950 | 2001-07-27 | Yes |
| 203-811 | XXXXXXXXXX | MULT | — | — |
| 203-812 | NEW HAVEN | 9147 | — | Yes |
| 203-813 | BYRAM | 7140 | — | Yes |
| 203-814 | BRIDGEPORT | 6388 | — | Yes |
| 203-815 | NEW HAVEN | 6388 | — | Yes |
| 203-816 | TRUMBULL | 4800 | 2001-03-14 | Yes |
| 203-817 | STAMFORD | 4950 | — | Yes |
| 203-818 | NORWALK | 7230 | — | Yes |
| 203-819 | WATERBURY | 4036 | — | Yes |
| 203-820 | NORWALK | 5562 | — | Yes |
| 203-821 | NEW HAVEN | 9147 | — | Yes |
| 203-822 | NORWALK | 7421 | — | Yes |
| 203-823 | NEW HAVEN | 318J | — | Yes |
| 203-824 | NEW HAVEN | 4036 | — | — |
| 203-825 | DANBURY | 9147 | — | — |
| 203-826 | DANBURY | 9147 | — | Yes |
| 203-827 | OLDGRNWICH | 7230 | 2004-07-19 | Yes |
| 203-828 | SEYMOUR | 4800 | — | Yes |
| 203-829 | NORWALK | 6624 | — | Yes |
| 203-830 | DANBURY | 9147 | — | Yes |
| 203-831 | NORWALK | 9147 | — | — |
| 203-832 | STAMFORD | 4036 | 2006-04-06 | Yes |
| 203-833 | NEW HAVEN | 6388 | 2015-07-29 | Yes |
| 203-834 | WILTON | 9147 | — | — |
| 203-835 | NORWALK | 6630 | — | — |
| 203-836 | NEW HAVEN | 6388 | 2011-12-06 | Yes |
| 203-837 | DANBURY | 9147 | — | Yes |
| 203-838 | NORWALK | 9147 | — | — |
| 203-839 | NORWALK | 6630 | — | — |
| 203-840 | NORWALK | 9147 | — | — |
| 203-841 | WATERBURY | 829J | — | Yes |
| 203-842 | NORWALK | 4800 | — | Yes |
| 203-843 | NEW HAVEN | 4036 | — | Yes |
| 203-844 | FAIRFIELD | 7230 | 2004-08-16 | Yes |
| 203-845 | NORWALK | 9147 | — | — |
| 203-846 | NORWALK | 9147 | — | — |
| 203-847 | NORWALK | 9147 | — | — |
| 203-848 | NEW HAVEN | 829J | — | Yes |
| 203-849 | NORWALK | 9147 | — | — |
| 203-850 | NEW HAVEN | 5562 | 2008-10-03 | Yes |
| 203-851 | NORWALK | 9147 | — | Yes |
| 203-852 | NORWALK | 9147 | — | — |
| 203-853 | NORWALK | 9147 | — | — |
| 203-854 | NORWALK | 9147 | — | — |
| 203-855 | NORWALK | 9147 | — | — |
| 203-856 | NORWALK | 6388 | — | — |
| 203-857 | NORWALK | 9147 | — | Yes |
| 203-858 | NORWALK | 6388 | — | — |
| 203-859 | NEW HAVEN | 7229 | — | Yes |
| 203-860 | — | — | ||
| 203-861 | GREENWICH | 9104 | — | — |
| 203-862 | GREENWICH | 9104 | — | — |
| 203-863 | GREENWICH | 9104 | — | — |
| 203-864 | BRIDGEPORT | 5562 | 2011-03-07 | Yes |
| 203-865 | NEW HAVEN | 9147 | — | — |
| 203-866 | NORWALK | 9147 | — | — |
| 203-867 | NEW HAVEN | 9147 | — | — |
| 203-868 | NEW HAVEN | 7421 | — | Yes |
| 203-869 | GREENWICH | 9104 | — | — |
| 203-870 | BRIDGEPORT | 4950 | — | Yes |
| 203-871 | BRANFORD | 7143 | — | Yes |
| 203-872 | CHESHIRE | 199F | — | Yes |
| 203-873 | BRIDGEPORT | 4036 | 2007-02-07 | Yes |
| 203-874 | MILFORD | 9147 | — | — |
| 203-875 | DARIEN | 7421 | — | Yes |
| 203-876 | MILFORD | 9147 | — | — |
| 203-877 | MILFORD | 9147 | — | — |
| 203-878 | MILFORD | 9147 | — | — |
| 203-879 | WOLCOTT | 9147 | — | — |
| 203-880 | TRUMBULL | 7143 | — | Yes |
| 203-881 | SEYMOUR | 9147 | — | Yes |
| 203-882 | MILFORD | 9147 | — | — |
| 203-883 | STAMFORD | 4800 | — | Yes |
| 203-884 | GUILFORD | 639C | — | Yes |
| 203-885 | DANBURY | 6388 | 2006-10-30 | Yes |
| 203-886 | MERIDEN | 829J | — | Yes |
| 203-887 | NEW HAVEN | 6624 | — | Yes |
| 203-888 | SEYMOUR | 9147 | — | — |
| 203-889 | NEW HAVEN | 4800 | — | Yes |
| 203-890 | STAMFORD | 9147 | 2001-07-27 | Yes |
| 203-891 | NEW HAVEN | 9147 | — | Yes |
| 203-892 | ANSONIDRBY | 6624 | 2010-11-08 | Yes |
| 203-893 | ANSONIDRBY | 6388 | 2007-06-29 | Yes |
| 203-894 | RIDGEFIELD | 9147 | — | Yes |
| 203-895 | TRUMBULL | 4036 | — | — |
| 203-896 | MADISON | 539F | — | Yes |
| 203-897 | STAMFORD | 7230 | 2008-08-20 | Yes |
| 203-898 | DARIEN | 7230 | 2005-01-31 | Yes |
| 203-899 | NORWALK | 9147 | — | — |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.