| Acjecology Limited | Professional & scientific | 2014 |
| Altamar Group Holdings Ltd | Real estate | 2026 |
| Blackpoint AI Limited | Information & communication | 2025 |
| BM Autos Essex Ltd | Wholesale & retail | 2023 |
| Charleston Court (West Mersea) Limited | Households | 1990 |
| Charter Project Consultancy Limited | Professional & scientific | 1979 |
| Deckchair Enterprises Limited | Wholesale & retail | 2024 |
| GMC Nominees Limited | Administrative & support | 2007 |
| Griffon Garage Services Limited | Wholesale & retail | 2008 |
| HMS Accounting Ltd | Professional & scientific | 2022 |
| Ipswich Group Developments Limited | Construction | 2021 |
| Marchar Limited | Administrative & support | 2012 |
| Mersea Ebikes Limited | Administrative & support | 2024 |
| Mersea Island Sports Association | Hospitality | 2019 |
| Micro Scooters Limited | Wholesale & retail | 2004 |
| Notbox Trading Limited | Administrative & support | 2012 |
| Onesource Industrial Limited | Administrative & support | 2019 |
| Regional Life Ltd | Other services | 2016 |
| SHE Shares Wealth Ltd | Other services | 2025 |
| SJC Design Ltd. | Professional & scientific | 2002 |
| Techspray Ltd | Construction | 2024 |
| THE UK Habitat Bank Limited | Professional & scientific | 2018 |
| Valkyrie Fish Company Limited | Agriculture & fishing | 2009 |
| Warhead Studios Limited | Information & communication | 2023 |
| West Mersea Marine (2002) Limited | Real estate | 2002 |