| 1-4 Sunnyside Limited | Real estate | 1992 |
| 3WAYSUPVENTOUX Limited | Professional & scientific | 2024 |
| 4 FUN Limited | Education | 2018 |
| 46 Sizewell Road (Leiston) Management Company Limited | Households | 2021 |
| 95-99 Holloway Road Limited | Real estate | 1997 |
| A French Production Ltd. | Arts & recreation | 2007 |
| A Vieira Field Services Ltd | Construction | 2016 |
| A&M Total Site Services Ltd | Water & waste | 2026 |
| A.G.S. (Chelmsford) Limited | Construction | 2003 |
| A.R.L. Equipment Ltd | Manufacturing | 2012 |
| A1 Carpets 4 U Limited | Wholesale & retail | 2009 |
| A2B UK Travel Ltd | Transport & logistics | 2023 |
| Aapex Accounting Ltd | Professional & scientific | 2025 |
| Abacus Business Services (Suffolk) Ltd | Professional & scientific | 2025 |
| Abacus Property Services 1 Limited | Real estate | 2013 |
| Abbey Properties (Suffolk) Ltd | Real estate | 2015 |
| Abery Business Consulting Ltd | Professional & scientific | 2021 |
| ABM Contract Services Ltd | Administrative & support | 2023 |
| AC Portraits Limited | Professional & scientific | 2021 |
| Acetate Pictures Limited | Information & communication | 2023 |
| Agora NOW East Anglia C.I.C. | Arts & recreation | 2025 |
| AJI Training & Construction Services Limited | Construction | 2016 |
| AJS Caravan & Home Services Ltd | Water & waste | 2024 |
| Alde Electrical Services Ltd | Construction | 2017 |
| Alde Engineering Limited | Manufacturing | 2011 |
| Alde Restoration & Construction Limited | Construction | 2019 |
| Alde Valley Spring Festival Limited | Other services | 2011 |
| Aldeburgh Construction Ltd | Construction | 2024 |
| Aldeburgh Design Limited | Professional & scientific | 2006 |
| Aldeburgh Education Ltd | Education | 2022 |
| Aldeburgh Music Limited | Extraterritorial | 1987 |
| Aldeburgh Rugby Club Community Interest Company | Arts & recreation | 2021 |
| Alderiver Properties Ltd | Real estate | 2019 |
| Aldridge Energy Electrical Contractors Limited | Construction | 2016 |
| Algorithm Films Limited | Information & communication | 2011 |
| Allegra Sounds Limited | Information & communication | 2019 |
| Amazing Aldeburgh Limited | Wholesale & retail | 2023 |
| Ambit Group Limited | Professional & scientific | 2006 |
| Ambit Limited | Professional & scientific | 2007 |
| Ambit Marketing Limited | Professional & scientific | 2005 |
| Anamar-Care Ltd | Health & social care | 2015 |
| Anatopath Limited | Professional & scientific | 2016 |
| Anchor Estate Company Limited(The) | Real estate | 1954 |
| Anchor Farms Limited | Agriculture & fishing | 2011 |
| Andres 2.0 Ltd | Wholesale & retail | 2024 |
| Anew Phase Ltd | Administrative & support | 2025 |
| Angel Dust Housekeeping & Management Limited | Administrative & support | 2008 |
| Angels Beauty Clinic (Saxmundham) Ltd | Other services | 2021 |
| Anniefitness Ltd | Education | 2023 |
| APM Sales Consulting Ltd | Information & communication | 2021 |
| Appeel Geoscience Ltd | Professional & scientific | 2015 |
| Arbus Holdings Limited | Financial services | 2021 |
| Areteflow Ltd | Education | 2026 |
| ASH Smoked Fishes Ltd | Wholesale & retail | 2025 |
| Assegai Management Ltd | Professional & scientific | 2023 |
| Assegai Properties Ltd | Real estate | 2024 |
| Async Services Ltd | Information & communication | 2024 |
| Auto Market Place Limited | Wholesale & retail | 2023 |
| Auxiliaris Limited | Professional & scientific | 2018 |
| Avbanu Limited | Information & communication | 2025 |
| Baba and Belly Ltd | Wholesale & retail | 2021 |
| Bagsvaerd Ltd | Construction | 2018 |
| Balneo (Suffolk) Ltd | Real estate | 2020 |
| Barkway Music Limited | Information & communication | 2012 |
| Barry Smith Builder (Suffolk) Limited | Construction | 2014 |
| BE Curious Limited | Professional & scientific | 2012 |
| BE Transport Limited | Extraterritorial | 2013 |
| Bees Buzz Public Relations Limited | Professional & scientific | 2015 |
| BEN Quorn Ltd | Construction | 2016 |
| Benhall Lodge Stables Limited | Agriculture & fishing | 2012 |
| Berbermedical Limited | Professional & scientific | 2017 |
| Bercem 71 Ltd | Other services | 2025 |
| Bethel Mortgages Ltd | Financial services | 2025 |
| Betty's Lettings Limited | Hospitality | 2018 |
| Bewilderbeest Ltd | Arts & recreation | 2019 |
| Big View Distribution Limited | Wholesale & retail | 2024 |
| Black Art Investments Ltd | Construction | 2010 |
| Blakes Installations Ltd | Administrative & support | 2012 |
| Blue Bear Bill INK Ltd | Other services | 2022 |
| Bluetail Birding Limited | Administrative & support | 2019 |
| Blyth Valley Business Services Limited | Professional & scientific | 2025 |
| Blythburgh Estate | Agriculture & fishing | 2009 |
| Boast Auctions Limited | Wholesale & retail | 2025 |
| Bouncing Bunnies Ltd | Hospitality | 2025 |
| Bracefield Limited | Construction | 1942 |
| Brains and Cheek (London) LLP | | 2011 |
| Brains&Cheek (2.0) Ltd | Professional & scientific | 2021 |
| Braiseworth Hall Farms Limited | Agriculture & fishing | 1950 |
| Brickfields Management Company (Aldeburgh) Limited | Real estate | 2012 |
| Bridekirk Properties Ltd | Real estate | 2021 |
| Bridge Street Construction Ltd | Construction | 2025 |
| Brightside Construction Suffolk Ltd | Construction | 2023 |
| Britten Pears Arts | Arts & recreation | 1970 |
| Brookfields Aldecar Limited | Households | 2021 |
| Brooks Architects Limited | Professional & scientific | 1985 |
| Brussels Green Enterprises Limited | Real estate | 2003 |
| Buffs Old Barn LLP | | 2015 |
| Business Growth East Anglia Ltd | Professional & scientific | 2018 |
| Buss Management Ltd | Real estate | 2020 |
| BYE Engineering (Melton) Limited | Manufacturing | 2007 |