All assignees
800 prefixes in 203 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 203-900 | GREENWICH | 612K | 2012-02-24 | Yes |
| 203-901 | NEW HAVEN | 6624 | — | Yes |
| 203-902 | NEW HAVEN | 639C | — | — |
| 203-903 | NEW HAVEN | 4800 | — | Yes |
| 203-904 | NORWALK | 6624 | — | Yes |
| 203-905 | STAMFORD | 7143 | — | Yes |
| 203-906 | ANSONIDRBY | 6388 | 2002-04-23 | Yes |
| 203-907 | NEW HAVEN | 829J | — | Yes |
| 203-908 | BRIDGEPORT | 6624 | 2006-04-05 | Yes |
| 203-909 | NEW HAVEN | 6388 | 2008-05-13 | Yes |
| 203-910 | WATERBURY | 6388 | — | — |
| 203-911 | XXXXXXXXXX | MULT | — | — |
| 203-912 | STAMFORD | 6388 | — | — |
| 203-913 | BRIDGEPORT | 6388 | — | — |
| 203-914 | STAMFORD | 612K | 2012-02-24 | Yes |
| 203-915 | NEW HAVEN | 6388 | — | — |
| 203-916 | BRIDGEPORT | 4800 | 2001-01-30 | Yes |
| 203-917 | DANBURY | 6388 | 2008-10-22 | Yes |
| 203-918 | STAMFORD | 4036 | — | — |
| 203-919 | NORWALK | 6624 | — | Yes |
| 203-920 | NEW CANAAN | 7230 | 2004-02-20 | Yes |
| 203-921 | STAMFORD | 9147 | — | Yes |
| 203-922 | HUNTINGTON | 9147 | — | Yes |
| 203-923 | BRIDGEPORT | 7230 | — | Yes |
| 203-924 | HUNTINGTON | 9147 | — | — |
| 203-925 | HUNTINGTON | 9147 | — | — |
| 203-926 | HUNTINGTON | 9147 | — | — |
| 203-927 | NEW HAVEN | 6388 | — | Yes |
| 203-928 | NEW HAVEN | 9147 | — | Yes |
| 203-929 | HUNTINGTON | 9147 | — | — |
| 203-930 | GREENWICH | 4800 | 2001-03-14 | Yes |
| 203-931 | NEW HAVEN | 9147 | — | Yes |
| 203-932 | NEW HAVEN | 9147 | — | — |
| 203-933 | NEW HAVEN | 9147 | — | — |
| 203-934 | NEW HAVEN | 9147 | — | — |
| 203-935 | MERIDEN | 4800 | — | Yes |
| 203-936 | NEW HAVEN | 9147 | 2008-09-12 | Yes |
| 203-937 | NEW HAVEN | 9147 | — | Yes |
| 203-938 | REDDING | 9147 | — | — |
| 203-939 | NORWALK | 612K | 2008-06-25 | Yes |
| 203-940 | STAMFORD | 9147 | — | Yes |
| 203-941 | SEYMOUR | 199F | 2010-09-21 | Yes |
| 203-942 | DANBURY | 6624 | — | Yes |
| 203-943 | NORWALK | 6624 | — | Yes |
| 203-944 | HUNTINGTON | 9147 | — | — |
| 203-945 | NORWALK | 9147 | — | Yes |
| 203-946 | NEW HAVEN | 9147 | — | — |
| 203-947 | DANBURY | 4036 | — | Yes |
| 203-948 | DANBURY | 6624 | — | Yes |
| 203-949 | WALLINGFD | 9147 | — | — |
| 203-950 | — | — | ||
| 203-951 | MILFORD | 7143 | — | Yes |
| 203-952 | NORWALK | 5562 | — | Yes |
| 203-953 | BRIDGEPORT | 6624 | 2001-07-27 | Yes |
| 203-954 | ANSONIDRBY | 829J | — | Yes |
| 203-955 | FAIRFIELD | 7230 | 2004-02-20 | Yes |
| 203-956 | NORWALK | 4950 | 2001-01-30 | Yes |
| 203-957 | NORWALK | 612K | 2011-05-25 | Yes |
| 203-958 | — | — | ||
| 203-959 | — | — | ||
| 203-960 | STAMFORD | 4950 | 2008-09-15 | Yes |
| 203-961 | STAMFORD | 9147 | — | Yes |
| 203-962 | STAMFORD | 9147 | — | Yes |
| 203-963 | NORWALK | 9147 | — | Yes |
| 203-964 | STAMFORD | 9147 | — | Yes |
| 203-965 | STAMFORD | 9147 | — | Yes |
| 203-966 | NEW CANAAN | 9147 | — | — |
| 203-967 | STAMFORD | 9147 | — | — |
| 203-968 | STAMFORD | 9147 | — | Yes |
| 203-969 | STAMFORD | 9147 | — | Yes |
| 203-970 | NORWALK | 4950 | 2011-04-04 | Yes |
| 203-971 | GREENWICH | 4950 | — | Yes |
| 203-972 | NEW CANAAN | 9147 | — | — |
| 203-973 | STAMFORD | 9147 | — | Yes |
| 203-974 | NEW HAVEN | 7143 | — | Yes |
| 203-975 | STAMFORD | 9147 | — | — |
| 203-976 | — | — | ||
| 203-977 | STAMFORD | 9147 | — | — |
| 203-978 | STAMFORD | 9147 | — | Yes |
| 203-979 | STAMFORD | 4036 | — | — |
| 203-980 | NEW HAVEN | 6388 | 2002-08-20 | Yes |
| 203-981 | NORWALK | 5562 | — | Yes |
| 203-982 | WATERBURY | 5562 | — | Yes |
| 203-983 | GREENWICH | 829J | — | Yes |
| 203-984 | NORWALK | 6388 | — | — |
| 203-985 | NEW HAVEN | 9147 | — | Yes |
| 203-986 | OLDGRNWICH | 7230 | 2004-02-20 | Yes |
| 203-987 | GREENWICH | 4800 | 2001-03-30 | Yes |
| 203-988 | NEW HAVEN | 4036 | — | — |
| 203-989 | STAMFORD | 4800 | — | Yes |
| 203-990 | OLDGRNWICH | 7230 | 2005-01-31 | Yes |
| 203-991 | NORWALK | 9147 | — | — |
| 203-992 | GREENWICH | 612K | 2006-05-12 | Yes |
| 203-993 | BRIDGEPORT | 6388 | 2006-07-20 | Yes |
| 203-994 | DANBURY | 6624 | 2001-12-14 | Yes |
| 203-995 | BRIDGEPORT | 7230 | 2008-10-08 | Yes |
| 203-996 | NEW HAVEN | 6624 | 2001-12-14 | Yes |
| 203-997 | ANSONIDRBY | 6624 | 2011-05-18 | Yes |
| 203-998 | STAMFORD | 4800 | 2004-10-15 | Yes |
| 203-999 | NEW HAVEN | 6624 | 2011-03-09 | Yes |
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.