| AB Electrical (UK) Limited | Construction | 2014 |
| AB Fairbrother Ltd | Construction | 2016 |
| Abacus END Point Assessment Ltd | Education | 2022 |
| Abatis Safety Services Limited | Professional & scientific | 2002 |
| Abbey Contractors (South) Ltd | Administrative & support | 2025 |
| Abbey View (Woodhall Spa) Management Company Limited | Households | 2019 |
| Abbeygate Rest Homes Limited | Health & social care | 1995 |
| Abbeyprint Limited | Manufacturing | 1992 |
| Abbi Pulling Racing and Promotions Limited | Arts & recreation | 2019 |
| ABC Lutherie Ltd | Manufacturing | 2008 |
| ABC Recruitment Ltd | Administrative & support | 2026 |
| ABC Trans Ltd | Transport & logistics | 2013 |
| Abilitie Education Limited | Education | 2021 |
| Abiz Hair Ltd | Other services | 2023 |
| Absaar Consulting Ltd | Professional & scientific | 2021 |
| Absolute EPM Limited | Information & communication | 2011 |
| Absurd Time Comics Ltd | Wholesale & retail | 2022 |
| Absurdtimesupply Ltd | Wholesale & retail | 2025 |
| Abtec Industries Limited | Manufacturing | 2002 |
| AC Drainage Limited | Water & waste | 2014 |
| Acast Group Ltd | Financial services | 2017 |
| Acast Industrial Flooring Limited | Construction | 1998 |
| Acclaim Industrial Doors Limited | Manufacturing | 2018 |
| Acdm Electrical Limited | Construction | 2026 |
| Ace Roofing and Maintenance Ltd | Construction | 2023 |
| Ace Roofing Services (Yorkshire) Ltd | Construction | 2025 |
| Ace Tones Entertainments Ltd | Administrative & support | 2004 |
| Ace Travel (Long Sutton) Limited | Transport & logistics | 2002 |
| Ace Tree Services Ltd | Administrative & support | 2023 |
| Acea Webb Limited | Wholesale & retail | 2017 |
| ACH Transport Limited | Transport & logistics | 2015 |
| Achievers Global Services Ltd | Wholesale & retail | 2025 |
| Aciercom Ltd | Wholesale & retail | 2025 |
| ACK Investments Limited | Real estate | 2024 |
| Acorn 2 Oak (2017) Ltd | Administrative & support | 2017 |
| Acorn Childcare (Spalding) Limited | Health & social care | 2008 |
| Acorn Corporate Enterprises Eastfield Limited | Other services | 2013 |
| Acorn Engineering (Holbeach) Limited | Manufacturing | 2005 |
| Acorn Landscapes (Cambs) Ltd | Administrative & support | 2025 |
| Acorn Tree Care & Landscapes (Cambs) Ltd | Construction | 2018 |
| Acroe Homes Limited | Real estate | 2019 |
| ACSSERVICES23 Ltd | Transport & logistics | 2026 |
| Activ 117 Ltd | Real estate | 2023 |
| Activ 118 Ltd | Real estate | 2023 |
| Activ 142 Ltd | Construction | 2023 |
| Activ 143 Ltd | Construction | 2023 |
| Activ 161 Ltd | Real estate | 2023 |
| Activ 75 Limited | Hospitality | 2024 |
| Activ 75 Trading Limited | Hospitality | 2024 |
| Activ 89 Ltd | Hospitality | 2023 |
| Activ 99 Ltd | Wholesale & retail | 2023 |
| Activ Commercial Ltd | Real estate | 2004 |
| Activ Estates Limited | Real estate | 2018 |
| Activ Group Support Ltd | Professional & scientific | 2023 |
| Active Personnel Ltd | Administrative & support | 2019 |
| Acts (Spalding) Ltd | Transport & logistics | 2012 |
| AD Warrior Ltd | Professional & scientific | 2018 |
| Adameli Ltd | Transport & logistics | 2026 |
| Adamist Ltd | Construction | 2024 |
| Adams Shop Ltd | Wholesale & retail | 2021 |
| Adamus G.B. Ltd | Manufacturing | 2024 |
| Adan Holdings Limited | Professional & scientific | 2002 |
| Adan Limited | Manufacturing | 1968 |
| Adcocks Minorcas Limited | Agriculture & fishing | 1948 |
| Adept Cloud Solutions Ltd | Information & communication | 2021 |
| ADI Drive Ltd | Transport & logistics | 2022 |
| ADI Tunet Ltd | Transport & logistics | 2020 |
| Adideone Ltd | Transport & logistics | 2020 |
| Adilar Ltd | Transport & logistics | 2024 |
| Aditzu Transport Limited | Transport & logistics | 2023 |
| Adrian Trofimov Limited | Transport & logistics | 2014 |
| Adrian Zaharia Limited | Transport & logistics | 2015 |
| Adrianek Ltd | Transport & logistics | 2021 |
| Adronos Ltd | Transport & logistics | 2025 |
| ADT Carpentry Ltd | Construction | 2014 |
| Adukas Ltd | Transport & logistics | 2017 |
| Adult & Childrens Ballet Ltd | Extraterritorial | 2019 |
| Adults Move Lincolnshire CIC | Health & social care | 2023 |
| Advance Carbon Offsetting Ltd | Information & communication | 2024 |
| Advance Finance Limited | Construction | 2011 |
| Advanced Roofing (Anglia) Ltd | Construction | 2020 |
| Advanced Roofing (Suffolk) Ltd | Construction | 2021 |
| Advanta Services Ltd | Construction | 2026 |
| ADVANTAGE8020 Limited | Professional & scientific | 2018 |
| Advatec International Transport Ltd | Transport & logistics | 2015 |
| Adverse Camber Vintage Ltd | Wholesale & retail | 2015 |
| Advi Services Limited | Administrative & support | 2025 |
| Adygeo Limited | Transport & logistics | 2021 |
| Aeglistus Holdings Limited | Financial services | 2024 |
| Aemy Ltd | Transport & logistics | 2025 |
| AEU Holding Ltd | Construction | 2025 |
| Affordable Builders Ltd. | Construction | 2017 |
| Afghan Fastfood Ltd | Hospitality | 2026 |
| African Blue (UK) Limited | Wholesale & retail | 2019 |
| Afterglow Holdings Ltd | Arts & recreation | 2026 |
| Afterglow Tanning Ltd | Other services | 2015 |
| Agenda Commercial Cleaning Services Ltd | Administrative & support | 2024 |
| Agenda Property Cleaning Ltd | Administrative & support | 2024 |
| Agri-Food Technology Academy Ltd | Professional & scientific | 2026 |
| Agricola Santa Eulalia (UK) Limited | Wholesale & retail | 2003 |