| AAG Management Limited | Professional & scientific | 2008 |
| AAL Logistics Limited | Transport & logistics | 2011 |
| AAM Cloud Solutions Ltd | Information & communication | 2022 |
| AAM Energy Limited | Manufacturing | 2010 |
| Aamtec Limited | Professional & scientific | 2007 |
| AAR Renovation Services Ltd | Construction | 2025 |
| Aaron Clarke Accountants Limited | Extraterritorial | 2015 |
| Aaron JD Ltd | Real estate | 2019 |
| Aaron Mckibbin Limited | Arts & recreation | 2025 |
| AAT2 Ltd | Transport & logistics | 2020 |
| AB Athlete Management Limited | Arts & recreation | 2022 |
| AB Auto Services Ltd | Wholesale & retail | 2019 |
| AB Canvas Store Ltd | Wholesale & retail | 2021 |
| AB Cars Imports Exports Brokerage Services Ltd | Wholesale & retail | 2026 |
| AB IT Holdings Ltd | Financial services | 2022 |
| AB IT Projects Ltd | Information & communication | 2018 |
| AB Specialist Installations Ltd | Professional & scientific | 2024 |
| AB Traffic Management Limited | Construction | 2026 |
| Ab.Animation Limited | Information & communication | 2024 |
| Abacus Blinds Suffolk Limited | Construction | 2012 |
| Abacus Building & Surveying Limited | Construction | 2005 |
| Abacus Business Solutions Ipswich Limited | Professional & scientific | 2016 |
| Abacus Cleaning East Anglia Ltd | Administrative & support | 2009 |
| Abacus Fire and Security Ltd | Construction | 2005 |
| Abacus Guardian Limited | Professional & scientific | 2011 |
| Abbey Aquatics & Reptiles Ltd | Wholesale & retail | 2017 |
| Abbey Protective Coatings Limited | Construction | 2017 |
| Abbeygate (D4.4N) LLP | | 2019 |
| Abbeygate Developments (Blakelands) Limited | Construction | 1995 |
| Abbeygate Developments (C4.1) Limited | Real estate | 2005 |
| Abbeygate Developments (Campbell Park) Limited | Real estate | 1990 |
| Abbeygate Developments (Grafton Gate 2) Limited | Real estate | 1994 |
| Abbeygate Developments Limited | Real estate | 1983 |
| Abbots Vale (Bury ST Edmunds) Management Company Limited | Households | 2025 |
| ABC Distribution Ltd | Transport & logistics | 2009 |
| ABC EOE Ltd | Administrative & support | 2026 |
| ABC Telecoms Ltd | Construction | 2021 |
| Abds (Anglia) Ltd | Professional & scientific | 2019 |
| ABE Transport Ltd | Transport & logistics | 2013 |
| Abegas Cyber Limited | Other services | 2022 |
| Abel & Keane Limited | Information & communication | 2012 |
| Abenable Ltd | Wholesale & retail | 2022 |
| Abeona Limited | Information & communication | 2010 |
| Abis Cars Limited | Other services | 2016 |
| Abiss Ltd | Wholesale & retail | 2018 |
| Able Roofing Suffolk Ltd | Construction | 2023 |
| Abongolden Limited | Transport & logistics | 2022 |
| Aborges Services Limited | Arts & recreation | 2025 |
| Abori International Ltd | Wholesale & retail | 2025 |
| Above & Beyond Care Ltd | Health & social care | 2011 |
| Above the Glass Ceiling Ltd | Hospitality | 2025 |
| Abram Scaffolding Ltd | Construction | 2023 |
| Absolute Rentals Limited | Real estate | 2006 |
| Absolute Risk Solutions (EA) Ltd | Financial services | 2022 |
| Absolute Risk Solutions (UK) Limited | Administrative & support | 2015 |
| Abstract PCM Ltd | Construction | 2019 |
| Abuku Ltd | Professional & scientific | 2015 |
| ACA Health & Safety Services Ltd | Public administration | 2019 |
| ACA Scientific & Medical Equipment Limited | Professional & scientific | 2021 |
| Acacia Beauty & Aesthetics Limited | Other services | 2020 |
| Academy Building Contracts Limited | Construction | 2005 |
| ACC7 Security Ltd | Administrative & support | 2025 |
| Accelerate Electrical Ltd | Construction | 2019 |
| Accelerate Facilities Ltd | Administrative & support | 2001 |
| Access Training East Anglia Limited | Education | 2019 |
| Accessible Designs Limited | Professional & scientific | 2004 |
| Accommodation by Gateway Limited | Real estate | 2021 |
| Account on Ltd | Administrative & support | 2018 |
| Account Watcher Ltd | Information & communication | 2026 |
| Accounts Hero Ltd | Professional & scientific | 2020 |
| Accounts Today Ltd | Extraterritorial | 2023 |
| Accuro FM Ltd | Administrative & support | 1995 |
| Acd&D LLP | | 2015 |
| Acdb Events Limited | Arts & recreation | 2016 |
| Ace Bugg Brickwork Ltd | Construction | 2015 |
| Ace Consultari Limited | Information & communication | 2021 |
| Ace Investments (East Anglia) Limited | Real estate | 2007 |
| Ace Logistics Group Limited | Construction | 2025 |
| Ace Property Limited | Real estate | 2016 |
| Aceae Nutra Limited | Manufacturing | 2018 |
| Acefast Computers Ltd | Other services | 2020 |
| Acer Safety Services Limited | Professional & scientific | 2005 |
| Acer Tree Specialists Ltd | Agriculture & fishing | 2011 |
| ACG Publications Limited | Information & communication | 2003 |
| Achar Enterprises Ltd | Health & social care | 2010 |
| Achievers School International Ltd | Education | 2024 |
| Achievers School Limited | Education | 2019 |
| ACJ Talent Partners Ltd Trading AS Respond Recruitment Ipswich Limited | Administrative & support | 2025 |
| ACM Body Repairs Ltd | Wholesale & retail | 2020 |
| Acorn Commercial Ltd | Real estate | 2021 |
| Acorn Company Management Limited | Professional & scientific | 2002 |
| Acorn Investments Suffolk Ltd | Real estate | 2025 |
| Acorn Residential Limited | Real estate | 2024 |
| Acorn Software Limited | Information & communication | 2021 |
| Acorn Trees Ipswich Limited | Administrative & support | 2026 |
| Acrocargo Express (UK) Co Limited | Administrative & support | 2009 |
| Across Legacy LLP | | 2025 |
| Across the Room Limited | Other services | 1994 |
| Acsod Ltd | Arts & recreation | 2026 |
| Acsons Ltd | Construction | 2023 |