| Art of Nature Consulting Limited | Professional & scientific | 2022 |
| Art of Perfume Ltd | Manufacturing | 2023 |
| Art Square Projects Ltd | Professional & scientific | 2016 |
| Art Superfan Ltd | Wholesale & retail | 2022 |
| ART5 Gallery Ltd | Wholesale & retail | 2014 |
| Artbox Design Limited | Professional & scientific | 2002 |
| Artbrighton Ltd | Professional & scientific | 2019 |
| Artcry Ltd | Financial services | 2020 |
| Arte&Stili Limited | Wholesale & retail | 2015 |
| Artech Development Ltd | Real estate | 2018 |
| Artech Holdings Limited | Financial services | 2020 |
| Artech SPV Development Ltd | Real estate | 2019 |
| Artelomis Limited | Professional & scientific | 2024 |
| Artem Barkhin Design Limited | Professional & scientific | 2025 |
| Artemisia Ltd | Financial services | 2026 |
| Artful Visions Ltd | Information & communication | 2014 |
| Arthouse Acoustics Limited | Arts & recreation | 2017 |
| Articulate Arts Ltd | Arts & recreation | 1997 |
| Articus Properties Limited | Real estate | 2020 |
| Artificium Games Ltd | Information & communication | 2025 |
| Artillery Cosmetics Ltd | Wholesale & retail | 2024 |
| Artisan Deli Market Limited | Wholesale & retail | 2021 |
| Artisan Plumbing & Heating Limited | Construction | 2021 |
| Artista Events Ltd | Arts & recreation | 2022 |
| Artistic Metalworks Limited | Manufacturing | 2012 |
| Artists & Socials Ltd | Manufacturing | 2019 |
| Artmagicmusic LP | | 2011 |
| Artraco Limited | Professional & scientific | 2013 |
| Artspace Brighton | Health & social care | 2013 |
| Artsustainability Ltd | Other services | 2024 |
| Artsy Clothing Ltd | Wholesale & retail | 2021 |
| Arum & Argentum Ltd | Wholesale & retail | 2024 |
| Arun Meade Limited | Information & communication | 2020 |
| Arun Waste Services Limited | Water & waste | 2008 |
| Arun-Autoparts Ltd | Wholesale & retail | 2024 |
| Arundel Marquees & Furniture Hire Ltd | Administrative & support | 2023 |
| Arundel Place Residents Company Limited | Households | 2002 |
| Arundel Property & Marketing Ltd | Households | 2019 |
| Arundel Property Ltd | Real estate | 2017 |
| Arundel Terrace LLP | | 2011 |
| Arundelar Ltd | Education | 2023 |
| Arwav Asset Management Ltd | Real estate | 2016 |
| Arxa IP Limited | Professional & scientific | 2026 |
| Arxine Limited | Manufacturing | 2017 |
| Aryzen Medical Ltd | Health & social care | 2024 |
| AS & S Properties Ltd. | Extraterritorial | 2008 |
| AS Franchise Ltd | Wholesale & retail | 2022 |
| AS Payment Solutions Ltd | Financial services | 2026 |
| ASA Structural Consultants Ltd | Construction | 2017 |
| Asad ALI Foods Ltd | Hospitality | 2026 |
| Asap Continental Ltd | Administrative & support | 2020 |
| Asc-Mascot C.I.C. | Other services | 2019 |
| Ascend Empire Group Ltd | Real estate | 2025 |
| Ascend Performance Ltd | Other services | 2021 |
| Ascend Property Sourcers Ltd | Real estate | 2023 |
| Ascendant Commerce Ltd | Wholesale & retail | 2026 |
| Ascot House Hove Management Limited | Real estate | 1982 |
| Ascs Construction Services Ltd | Professional & scientific | 2016 |
| ASH Project Sevices Ltd | Construction | 2022 |
| ASH Site Security Ltd | Administrative & support | 2022 |
| Ashbee Estates Limited | Real estate | 2014 |
| Ashcroft Custom Kitchens Ltd | Construction | 2026 |
| Ashcroft Kitchens Ltd | Construction | 2026 |
| Ashdel Limited | Real estate | 2016 |
| Ashdown Property Investments Ltd | Construction | 2013 |
| Ashdown Systems Ltd | Information & communication | 2026 |
| Ashenbury Investments Ltd | Real estate | 2019 |
| Ashling Films Ltd | Information & communication | 2022 |
| Ashling Limited | Real estate | 2006 |
| Ashored Carpentry & Construction Ltd | Manufacturing | 2025 |
| Ashovi & Regsiv UK Ltd | Wholesale & retail | 2021 |
| Ashram Retreats Limited | Administrative & support | 2025 |
| Ashton Commercial Limited | Professional & scientific | 2011 |
| Ashton Rail Services Ltd | Professional & scientific | 2014 |
| Ashtons Hospital Pharmacy Services Limited | Health & social care | 2005 |
| Ashtons Primary Care Services Limited | Health & social care | 2021 |
| Ashurst Lodge Freehold Limited | Households | 2023 |
| Ashurst Preston Ltd | Real estate | 2026 |
| Ashwatech Ltd | Information & communication | 2026 |
| Ashworth Creative Services Ltd | Professional & scientific | 2018 |
| ASI Reality Limited | Financial services | 2018 |
| Asia Pacific Opportunity Consultants Ltd | Professional & scientific | 2021 |
| Asis Patel Ltd | Professional & scientific | 2019 |
| ASK J Vape Expert Ltd | Wholesale & retail | 2024 |
| ASK Research Partners Ltd | Information & communication | 2023 |
| Asked AI Limited | Information & communication | 2025 |
| Askew & SON Building Contractors Limited | Construction | 1999 |
| Askforme Ltd | Information & communication | 2013 |
| Asks Property Service Ltd | Real estate | 2025 |
| Aslan Grill Ltd | Hospitality | 2022 |
| Asmin Handyman Ltd | Construction | 2019 |
| Asociat Ltd | Professional & scientific | 2021 |
| ASP Practice Limited | Health & social care | 2016 |
| Aspen Living Ltd | Real estate | 2019 |
| Aspinall Consultants Limited | Professional & scientific | 2014 |
| Aspire Home Carers Limited | Health & social care | 2014 |
| Aspire Resourcing GCC Limited | Administrative & support | 2009 |
| Aspire Stores Limited | Wholesale & retail | 2025 |
| Aspire Sustainability Consulting Ltd | Professional & scientific | 2023 |
| Aspo Property Ltd | Real estate | 2026 |