| 2023-24 | Mildenhall Town | to | Isthmian League | |
| 2023-24 | Newmarket Town | to | Isthmian League | |
| 2022-23 | Ipswich Wanderers | to | Isthmian League | |
| 2021-22 | Wroxham | to | Isthmian League | |
| 2021-22 | Gorleston | to | Isthmian League | |
| 2020-21 | Stowmarket Town | to | Isthmian League | |
| 2018-19 | Histon | to | Southern League | |
| 2017-18 | Coggeshall Town | to | Isthmian League | |
| 2017-18 | Felixstowe & Walton United | to | Isthmian League | |
| 2016-17 | Mildenhall Town | to | Isthmian League | (returned 2019) |
| 2015-16 | Norwich United | to | Isthmian League | (returned 2018) |
| 2013-14 | Brightlingsea Regent | to | Isthmian League | |
| 2012-13 | Dereham Town | to | Isthmian League | (returned 2023) |
| 2011-12 | Wroxham | to | Isthmian League | (returned 2017) |
| 2010-11 | Leiston | to | Isthmian League | |
| 2009-10 | Needham Market | to | Isthmian League | |
| 2008-09 | Lowestoft Town | to | Isthmian League | |
| 2007-08 | Soham Town Rangers | to | Southern League | (returned 2022) |
| 2005-06 | Bury Town | to | Isthmian League | |
| 2005-06 | AFC Sudbury | to | Isthmian League | |
| 2003-04 | Maldon Town | to | Southern League | |
| 1999-00 | Histon | to | Southern League | (returned 2017) |
| 1996-97 | Wisbech Town | to | Southern League | (returned 2002) |
| 1990-91 | Braintree Town | to | Southern League | |
| 1989-90 | Sudbury Town | to | Southern League | (returned 1997) |
| 1986-87 | Bury Town | to | Southern League | (returned 1996) |
| 1963-64 | Bury Town | to | Southern League | (returned 1976) |
| 1957-58 | Cambridge United | to | Southern League | |
| 1957-58 | Clacton Town | to | Southern League | (returned 1964) |
| 1953-54 | Kings Lynn | to | Southern League | (returned 1958) |
| 1951-52 | Wisbech Town | to | Southern League | (returned 1958) |
| 1936-37 | Chelmsford City | to | Southern League |
| 2024-25 2024-25 2023-24 |
Brantham Athletic Downham Town Mildenhall Town |
to to to |
Isthmian League Isthmian League Isthmian League |
|
| 2023-24 | Newmarket Town | to | Isthmian League | |
| 2022-23 | Ipswich Wanderers | to | Isthmian League | (returned 2025) |
| 2021-22 | Wroxham | to | Isthmian League | |
| 2021-22 | Gorleston | to | Isthmian League | |
| 2020-21 | Stowmarket Town | to | Isthmian League | (returned 2024) |
| 2018-19 | Histon | to | Southern League | |
| 2017-18 | Coggeshall Town | to | Isthmian League | (returned 2024) |
| 2017-18 | Felixstowe & Walton United | to | Isthmian League | |
| 2016-17 | Mildenhall Town | to | Isthmian League | (returned 2019) |
| 2015-16 | Norwich United | to | Isthmian League | (returned 2018) |
| 2013-14 | Brightlingsea Regent | to | Isthmian League | |
| 2012-13 | Dereham Town | to | Isthmian League | (returned 2023) |
| 2011-12 | Wroxham | to | Isthmian League | (returned 2017) |
| 2010-11 | Leiston | to | Isthmian League | |
| 2009-10 | Needham Market | to | Isthmian League | |
| 2008-09 | Lowestoft Town | to | Isthmian League | |
| 2007-08 | Soham Town Rangers | to | Southern League | (returned 2022) |
| 2005-06 | Bury Town | to | Isthmian League | |
| 2005-06 | AFC Sudbury | to | Isthmian League | |
| 2003-04 | Maldon Town | to | Southern League | |
| 1999-00 | Histon | to | Southern League | (returned 2017) |
| 1996-97 | Wisbech Town | to | Southern League | (returned 2002) |
| 1990-91 | Braintree Town | to | Southern League | |
| 1989-90 | Sudbury Town | to | Southern League | (returned 1997) |
| 1986-87 | Bury Town | to | Southern League | (returned 1996) |
| 1963-64 | Bury Town | to | Southern League | (returned 1976) |
| 1957-58 | Cambridge United | to | Southern League | |
| 1957-58 | Clacton Town | to | Southern League | (returned 1964) |
| 1953-54 | Kings Lynn | to | Southern League | (returned 1958) |
| 1951-52 | Wisbech Town | to | Southern League | (returned 1958) |
| 1936-37 | Chelmsford City | to | Southern League |