| ABS Gym Swaffham Ltd | Arts & recreation | 2025 |
| Accessible Living Homes Ltd | Construction | 2025 |
| Accounting Solutions (Downham Market) Ltd | Professional & scientific | 2018 |
| Accountlab Properties Ltd | Real estate | 2023 |
| Ace Cabs (West Norfolk) Limited | Transport & logistics | 2024 |
| Ace Connections (East) Ltd | Construction | 2021 |
| Ace Event Catering Ltd | Manufacturing | 2023 |
| Acentra Limited | Wholesale & retail | 2011 |
| Acorn Waste Tech Services Ltd | Water & waste | 2017 |
| Action IT Electrical Limited | Professional & scientific | 2006 |
| Actionshield Limited | Construction | 1995 |
| Adams Yacht Services Limited | Manufacturing | 2023 |
| ADD Consultancy Ltd | Professional & scientific | 2010 |
| Admiral Windows and Fire Escapes Limited | Construction | 2010 |
| Admissions Solutions Limited | Education | 2023 |
| ADN Fragrances Ltd | Wholesale & retail | 2026 |
| Adrian Dewhirst Upvc Windows & Doors Limited | Construction | 2004 |
| ADT Distribution Ltd | Water & waste | 2021 |
| ADT Housing & Property Limited | Real estate | 2025 |
| Advance Engineering (UK) Ltd | Manufacturing | 2010 |
| Advance Heating & Plumbing (Lincs) Limited | Construction | 2013 |
| Advanced Building Projects (East Anglia) Limited | Construction | 2018 |
| Advanced Building Projects Limited | Construction | 2015 |
| Advanced Plastic & Aesthetic Consultants Ltd | Health & social care | 2018 |
| Advanced Thermosets Limited | Manufacturing | 1993 |
| Advanced Water Treatment (UK) Ltd | Professional & scientific | 2005 |
| Aeon Pharma Ltd | Professional & scientific | 2021 |
| Aequitas Education Ltd | Education | 2018 |
| Aerial Fitness and FUN Limited | Arts & recreation | 2022 |
| Aero Care Solutions Limited | Professional & scientific | 2026 |
| Aerospy Ltd | Extraterritorial | 2025 |
| Aesthetic Clinical Training Academy Limited | Health & social care | 2019 |
| AF Garden Maintenance Ltd | Administrative & support | 2025 |
| AFE Group Limited | Manufacturing | 1999 |
| Afrocari Naturals Ltd | Manufacturing | 2021 |
| Agedum Ltd | Administrative & support | 2025 |
| AGH Investment Group Limited | Real estate | 2026 |
| AGH Property Rentals Ltd | Real estate | 2024 |
| Agile Trustee Limited | Professional & scientific | 2023 |
| Agnes Polish Furniture Limited | Wholesale & retail | 2018 |
| AGT21 Ltd | Wholesale & retail | 2021 |
| AH FM Ltd | Construction | 2024 |
| AH Searle Properties Ltd | Real estate | 2021 |
| AH Trading Ltd | Wholesale & retail | 2026 |
| AH Windows Limited | Manufacturing | 2013 |
| AI Bits Ltd | Information & communication | 2024 |
| AIM Electrical and Mechanical Ltd | Construction | 2017 |
| AIM Electrical Services Limited | Construction | 2017 |
| Air Abode Ltd | Construction | 2019 |
| Airfield Eggs Ltd | Wholesale & retail | 2019 |
| Airport Link Taxis Limited | Extraterritorial | 2002 |
| Airport Travel Services Ltd | Transport & logistics | 2018 |
| Airstream Rentals Ltd | Extraterritorial | 2008 |
| Airwave Heating Ltd | Construction | 2026 |
| Aism Holdings Limited | Financial services | 2024 |
| AJD Electrical Limited | Construction | 2018 |
| AJL Group Holdings Ltd | Manufacturing | 2018 |
| Akois Ltd | Transport & logistics | 2013 |
| AL Power Ltd | Energy | 2014 |
| Alameda Properties Limited | Real estate | 2013 |
| Alan Mitchell Plasterers Limited | Construction | 2012 |
| Alanai Consulting Limited | Administrative & support | 2014 |
| Alarming UK Limited | Administrative & support | 2002 |
| Albe Property Co Limited | Construction | 2022 |
| Albha Tech Solutions Ltd | Information & communication | 2025 |
| Albie Dental Limited | Health & social care | 2024 |
| Albino Rhino Ltd | Professional & scientific | 2018 |
| Albion Prime Trading Ltd | Wholesale & retail | 2025 |
| Alderforth Associates Ltd | Real estate | 2025 |
| Alderney Livestock Company Ltd | Agriculture & fishing | 2014 |
| Aldridge Restoration Ltd | Construction | 2004 |
| Alec Lochore Event & Equestrian Consultancy Ltd. | Arts & recreation | 2014 |
| Alectrona Consultancy Ltd | Professional & scientific | 2022 |
| Alex Symonds Electrical Limited | Construction | 2014 |
| Alex Symonds Property Management Ltd | Real estate | 2019 |
| Alexander & Gregg Hair Co Limited | Other services | 2019 |
| Alexcadar Limited | Health & social care | 2019 |
| Alfapro Engineering Ltd | Professional & scientific | 2024 |
| Alfred Court Freehold Limited | Hospitality | 2004 |
| Alfred Court Management Company Limited | Hospitality | 1972 |
| Alfred G Pearce Limited | Manufacturing | 1970 |
| Alico Investments Limited | Administrative & support | 2019 |
| Alive West Norfolk | Arts & recreation | 2019 |
| Alkhamware Limited | Information & communication | 2017 |
| ALL Kind Scaffolding Limited | Extraterritorial | 2016 |
| ALL One Construction Limited | Construction | 2022 |
| ALL Saints (KL) Management Company Limited | Real estate | 2015 |
| ALL Saints Barns (Management Company) Limited | Households | 2024 |
| ALL the Details Limited | Construction | 2022 |
| Allan Industrial Roofing Ltd | Construction | 2019 |
| Allen Private Clients Ltd | Administrative & support | 2021 |
| Allium Way Management Company Limited | Households | 2025 |
| Allsquare Properties Limited | Construction | 2009 |
| Almeida Despatch Ltd | Transport & logistics | 2021 |
| Almond Arch Properties Ltd | Real estate | 2022 |
| Almost Saints Ltd | Extraterritorial | 2019 |
| ALN Painting and Decorating Ltd | Construction | 2023 |
| Alna-Health Ltd | Health & social care | 2023 |
| Alpha Canine Specialists Limited | Administrative & support | 2021 |
| Alphafox Ltd | Information & communication | 2018 |