All assignees
596 prefixes in 231 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 231-835 | GLEN LAKE | 6534 | 2002-08-30 | Yes |
| 231-836 | EVART | 2550 | 2002-08-27 | — |
| 231-837 | FREMONT | 9748 | — | — |
| 231-838 | PETOSKEY | 6534 | 2002-03-29 | — |
| 231-839 | LAKE CITY | 0702 | — | — |
| 231-842 | CADILLAC | 2550 | 2002-08-27 | — |
| 231-843 | LUDINGTON | 0695 | — | — |
| 231-844 | INDIAN RIV | 6120 | 2001-06-18 | Yes |
| 231-845 | LUDINGTON | 0695 | — | — |
| 231-846 | CADILLAC | 2964 | — | Yes |
| 231-848 | WELLSTON | 0703 | — | — |
| 231-852 | LUDINGTON | 6534 | — | Yes |
| 231-853 | RAVENNA | 0695 | — | Yes |
| 231-854 | HESPERIA | 0695 | — | — |
| 231-855 | MUSKEGON | 6534 | — | Yes |
| 231-856 | MORLEY | 9323 | — | Yes |
| 231-859 | DUBLIN | 0703 | — | — |
| 231-861 | SHELBY | 0695 | — | Yes |
| 231-862 | HOXEYVILLE | 0704 | — | Yes |
| 231-864 | BEAR LAKE | 0702 | — | — |
| 231-865 | FRUITPORT | 0695 | — | Yes |
| 231-866 | SUTTONSBAY | 6534 | 2002-08-30 | Yes |
| 231-867 | CHIPPEWALK | 0671 | — | Yes |
| 231-869 | PENTWATER | 0695 | — | Yes |
| 231-871 | BEULAH | 6534 | — | Yes |
| 231-872 | REED CITY | 6534 | — | Yes |
| 231-873 | HART | 0695 | — | — |
| 231-874 | WOLVERINE | 2550 | 2002-08-27 | — |
| 231-875 | FRUITPORT | 991E | — | Yes |
| 231-876 | CADILLAC | 9323 | — | Yes |
| 231-877 | NORTHPORT | 2550 | — | — |
| 231-878 | CADILLAC | 6003 | 2002-07-19 | — |
| 231-879 | FIFE LAKE | 9323 | — | Yes |
| 231-880 | MUSKEGON | 622J | 2021-09-08 | Yes |
| 231-881 | PETOSKEY | 6534 | — | Yes |
| 231-882 | BEULAH | 9323 | — | Yes |
| 231-883 | TRAVERSECY | 6534 | — | — |
| 231-884 | CADILLAC | 6534 | — | Yes |
| 231-885 | MESICK | 0704 | — | Yes |
| 231-886 | KALKASKA | 6534 | — | Yes |
| 231-887 | MANISTEE | 6534 | — | Yes |
| 231-888 | TWIN LAKE | 543C | 2015-06-16 | Yes |
| 231-889 | ONEKAMA | 9323 | — | Yes |
| 231-890 | TRAVERSECY | 9323 | — | — |
| 231-893 | WHITEHALL | 0695 | — | — |
| 231-894 | WHITEHALL | 0695 | — | Yes |
| 231-898 | CARR | 0683 | — | Yes |
| 231-899 | NORTHPORT | 2550 | 2002-08-27 | — |
| 231-900 | MUSKEGON | 965H | 2019-05-13 | Yes |
| 231-902 | HART | 817J | 2001-08-27 | — |
| 231-903 | MUSKEGON | 6120 | 2002-04-29 | Yes |
| 231-906 | — | — | ||
| 231-907 | LUDINGTON | 6534 | 2002-09-03 | Yes |
| 231-908 | MCBAIN | 2550 | 2002-08-27 | — |
| 231-911 | XXXXXXXXXX | MULT | — | — |
| 231-912 | REED CITY | 6534 | 2002-08-30 | Yes |
| 231-916 | MANCELONA | 6120 | 2001-06-18 | Yes |
| 231-920 | CADILLAC | 6534 | — | — |
| 231-922 | TRAVERSECY | 9323 | — | — |
| 231-923 | HART | 2964 | 2001-05-18 | Yes |
| 231-924 | FREMONT | 9323 | — | — |
| 231-925 | SCOTTVILLE | 2550 | 2002-08-27 | Yes |
| 231-928 | FREMONT | 9323 | — | Yes |
| 231-929 | TRAVERSECY | 9323 | — | — |
| 231-930 | BEULAH | 3535 | 2001-06-18 | Yes |
| 231-932 | TRAVERSECY | 9323 | — | — |
| 231-933 | TRAVERSECY | 9323 | — | — |
| 231-935 | TRAVERSECY | 9323 | — | — |
| 231-936 | SCOTTVILLE | 829J | 2001-06-18 | Yes |
| 231-937 | HOWARDCITY | 0695 | — | Yes |
| 231-938 | TRAVERSECY | 9323 | — | Yes |
| 231-939 | PETOSKEY | 6534 | 2017-08-09 | Yes |
| 231-941 | TRAVERSECY | 9323 | — | — |
| 231-942 | CADILLAC | 6003 | 2001-06-18 | Yes |
| 231-943 | TRAVERSECY | 9323 | — | Yes |
| 231-944 | TRAVERSECY | 9245 | — | Yes |
| 231-946 | TRAVERSECY | 9323 | — | — |
| 231-947 | TRAVERSECY | 9323 | — | — |
| 231-950 | — | — | ||
| 231-955 | MUSKEGON | 6534 | — | Yes |
| 231-958 | — | — | ||
| 231-959 | — | — | ||
| 231-963 | MCBAIN | 516J | 2022-02-28 | Yes |
| 231-966 | FREESOIL | 516J | 2022-02-22 | Yes |
| 231-968 | CADILLAC | 991E | 2021-09-16 | Yes |
| 231-970 | BEAR LAKE | 6534 | 2002-08-30 | Yes |
| 231-972 | MECOSTA | 0671 | — | — |
| 231-974 | GRANT | 2550 | 2002-08-27 | Yes |
| 231-976 | — | — | ||
| 231-977 | MACKINAWCY | 965H | 2020-02-19 | Yes |
| 231-981 | WHITEHALL | 0695 | — | Yes |
| 231-988 | — | — | ||
| 231-989 | — | — | ||
| 231-994 | LKLEELANAU | 3535 | 2005-01-19 | Yes |
| 231-995 | TRAVERSECY | 9323 | — | — |
| 231-999 | CENTRAL LK | 543C | 2015-08-24 | 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.