| A&F Chelmsford Ltd | Real estate | 2025 |
| A&F Dog Services Limited | Extraterritorial | 2022 |
| A&F Essex Limited | Real estate | 2014 |
| A&F Global Invest Ltd | Real estate | 2015 |
| A&G Capital Limited | Construction | 2017 |
| A&H Driving School Limited | Education | 2024 |
| A&H Goldsmith Limited | Wholesale & retail | 2025 |
| A&I Couriers Limited | Transport & logistics | 2024 |
| A&I Traders Ltd | Wholesale & retail | 2026 |
| A&Z Shop Limited | Wholesale & retail | 2025 |
| A-Star Therapies Ltd | Other services | 2014 |
| A. Buhov Ltd | Transport & logistics | 2015 |
| A.B. Detailing Grays Ltd | Administrative & support | 2026 |
| A.D.X. Construction Ltd | Construction | 2024 |
| A.Dedaj Construction Ltd | Construction | 2021 |
| A.I-Streamline Ltd | Information & communication | 2026 |
| A.L.M. Health and Safety Consultants Ltd | Construction | 2025 |
| A.M Deliveroo Limited | Transport & logistics | 2023 |
| A.M.B Prime Properties Ltd | Real estate | 2025 |
| A.M.J.D Consulting Ltd | Information & communication | 2019 |
| A.W Resources Ltd | Information & communication | 2017 |
| A2B Property Development Ltd | Real estate | 2021 |
| A2D Consultancy Ltd | Information & communication | 2012 |
| A2Z Care Services Limited | Health & social care | 2019 |
| A4U Driver Ltd | Transport & logistics | 2020 |
| A5 Financial Services Ltd | Professional & scientific | 2025 |
| AA Cladding Ltd | Construction | 2016 |
| AA Team Entertainment Limited | Information & communication | 2022 |
| AAA Consulting Ltd | Professional & scientific | 2019 |
| AAA UK Properties Ltd | Real estate | 2019 |
| Aacc Services Ltd | Wholesale & retail | 2016 |
| Aadhya Courier Services Limited | Transport & logistics | 2025 |
| Aairah Stores Limited | Wholesale & retail | 2025 |
| Aakash Trading Limited | Wholesale & retail | 2025 |
| Aakaz Traders Ltd | Wholesale & retail | 2020 |
| Aale Imran Tours UK Ltd | Education | 2014 |
| Aamrand Limited | Real estate | 2024 |
| Aarai Solutions Ltd | Information & communication | 2026 |
| Aarizraza Limited | Hospitality | 2024 |
| Aaron & Leah Limited | Administrative & support | 2023 |
| Aasra Social Care Limited | Health & social care | 2025 |
| AAT Consultancy Ltd | Health & social care | 2023 |
| AAV Property Ltd | Real estate | 2022 |
| AAV Transport Ltd | Transport & logistics | 2013 |
| Aavy Hospitality Ltd | Hospitality | 2022 |
| AB Haulage Ltd | Transport & logistics | 2026 |
| AB Healthcare Solutions Limited | Health & social care | 2014 |
| AB Liontrade Limited | Construction | 2021 |
| AB Perfect Choice Services Ltd | Information & communication | 2019 |
| ABA Pathways Limited | Education | 2022 |
| Abacons Global Services Limited | Administrative & support | 2013 |
| Abalcar Ltd | Administrative & support | 2016 |
| Abbey Memorials Limited | Other services | 1982 |
| Abbt Ltd | Health & social care | 2014 |
| ABC Home Solutions Limited | Administrative & support | 2017 |
| ABC Integrity Ltd | Construction | 2015 |
| ABC Transfers and Crew Logistics Ltd | Transport & logistics | 2011 |
| ABC Wizards Limited | Information & communication | 2000 |
| ABD Logistics Ltd | Transport & logistics | 2021 |
| Abday Ltd | Health & social care | 2023 |
| Abdheem Limited | Information & communication | 2025 |
| ABI Gjms UK Limited | Hospitality | 2016 |
| Abiam Consultancy Limited | Health & social care | 2013 |
| Abidjan House Ltd | Hospitality | 2026 |
| Abidoy Consults Ltd | Health & social care | 2023 |
| Abidworks Ltd | Wholesale & retail | 2024 |
| Abike Services Ltd | Health & social care | 2020 |
| Abikem Limited | Health & social care | 2018 |
| Abishoy Alpha Ventures Ltd | Financial services | 2025 |
| Abivia Investments Limited | Transport & logistics | 2017 |
| ABJ Center Ltd | Hospitality | 2026 |
| ABJ Contractors Ltd | Manufacturing | 2021 |
| Able and Hale Limited | Arts & recreation | 2022 |
| Able Electrical Contractors Limited | Construction | 2017 |
| Able Piling & Construction Limited | Construction | 2021 |
| Above Parkour Academy Limited | Education | 2022 |
| ABS Ceramics and Stone Ltd | Construction | 2022 |
| Absolute PR Ltd. | Information & communication | 2010 |
| ABT Removals Ltd | Transport & logistics | 2020 |
| ABU Developments Ltd | Construction | 2022 |
| AC Insulation Ltd | Construction | 2003 |
| AC Logistic Valcea Ltd | Transport & logistics | 2021 |
| AC Smart Build Ltd | Construction | 2017 |
| ACADEMY4SUCCESS Ltd | Real estate | 2016 |
| Acc&Db Ltd | Transport & logistics | 2024 |
| Access 24/7 Health Care Ltd | Health & social care | 2018 |
| Access Builders Direct Ltd | Construction | 2011 |
| Access Repairs & Servicing Limited | Manufacturing | 2019 |
| Accort Ltd | Transport & logistics | 2019 |
| Accounting 4ALL Ltd | Professional & scientific | 2016 |
| Accuplus Accountancy Ltd | Professional & scientific | 2024 |
| Ace Training Limited | Construction | 2005 |
| Acer Defence Limited | Information & communication | 2025 |
| Aces Business Services Limited | Wholesale & retail | 2019 |
| Acfe Marto Services Ltd | Wholesale & retail | 2017 |
| ACN Accountants Limited | Extraterritorial | 2015 |
| Acorn Decorators Merchants Limited | Wholesale & retail | 1982 |
| Acorn Tiles Limited | Wholesale & retail | 2022 |
| Acorn Truck Sales Limited | Wholesale & retail | 1988 |
| Acrc Electrical Ltd | Construction | 2026 |