| AHMEDAKHTAR1 Ltd | Real estate | 2021 |
| AHMEDAKHTAR2 Ltd | Real estate | 2023 |
| Ahuprime Limited | Real estate | 2018 |
| AI Auto Motion Ltd | Transport & logistics | 2026 |
| Aienai Limited | Administrative & support | 2021 |
| Aimee Treasure Marketing Ltd | Professional & scientific | 2024 |
| Aimee Victoria Long Ltd | Administrative & support | 2019 |
| Aimu Ltd | Wholesale & retail | 2026 |
| Air Art Ltd | Wholesale & retail | 2026 |
| Air Hosting Ltd | Hospitality | 2018 |
| Air RS Consulting Ltd | Professional & scientific | 2026 |
| Air RS Holdings Ltd | Financial services | 2026 |
| Airstream International Group Limited | Wholesale & retail | 1988 |
| Airtec Solutions Ltd | Manufacturing | 2022 |
| Airvana Solutions Limited | Wholesale & retail | 2025 |
| AIV - EAT Just LLP | | 2021 |
| AIV Just CV LLP | | 2021 |
| AJ Academy Ltd | Other services | 2022 |
| AJ Galaxy Limited | Transport & logistics | 1998 |
| AJ Online Store Ltd | Wholesale & retail | 2023 |
| AJC Group Holdings Limited | Professional & scientific | 2019 |
| Ajkp Solutions Ltd | Information & communication | 2015 |
| AJM Prop. Management Ltd | Real estate | 2023 |
| AJS Education Assessment Consultancy Ltd | Education | 2023 |
| AK Sports Management Limited | Arts & recreation | 2007 |
| AK Tech Delivery Ltd | Professional & scientific | 2026 |
| AKA Developments Greenview Ltd | Construction | 2018 |
| AKD Materials Consulting Limited | Professional & scientific | 2007 |
| Akeman Property Company Limited | Real estate | 1966 |
| Akh's Auto LAB Limited | Wholesale & retail | 2025 |
| AKP Eyecare Limited | Wholesale & retail | 2017 |
| AKR Technologies (BC) LLP | | 2023 |
| Akshaya Destinus SPV II Lead LLP | | 2023 |
| Akshaya Destinus SPV II LLP | | 2023 |
| Akyaka Limited | Hospitality | 2021 |
| AL1 Design Ltd | Construction | 2023 |
| AL2 Engineering Ltd | Construction | 2026 |
| AL3 Restaurant Limited | Manufacturing | 2025 |
| Alan F FOX Consulting Ltd | Professional & scientific | 2022 |
| Alan Higgs Architects Limited | Professional & scientific | 2021 |
| Alan Janes Limited | Arts & recreation | 2003 |
| Aland Aran Ltd | Other services | 2025 |
| Alaya & Co Travel Limited | Administrative & support | 2026 |
| ALB Brickwork Limited | Construction | 2018 |
| ALB Group Holdings Ltd | Financial services | 2023 |
| ALB Property Solutions Ltd | Manufacturing | 2020 |
| ALB Waterproofing Ltd | Construction | 2020 |
| Albacore Analytics Ltd | Professional & scientific | 2026 |
| Alban Accounting & Tax Services Ltd | Professional & scientific | 2014 |
| Alban Cars Ltd | Transport & logistics | 2024 |
| Alban City Free School Ltd | Education | 2011 |
| Alban Decorating Ltd | Construction | 2020 |
| Alban Electric Vans Ltd | Wholesale & retail | 2018 |
| Alban Knight Ltd | Other services | 2021 |
| Alban Locksmiths Limited | Administrative & support | 2011 |
| Alban Mouldings Ltd | Construction | 2025 |
| Alban Osteopathy Ltd | Health & social care | 2024 |
| Alban Park Management Services Limited | Professional & scientific | 2015 |
| Alban Property Company Limited | Real estate | 2018 |
| Alban RTM Company Limited | Households | 2007 |
| Alban Structural Maintenance Limited | Construction | 1991 |
| Alban Structural Maintenance Properties Ltd | Real estate | 2025 |
| Alban Tattoo Company Ltd | Other services | 2014 |
| Alban Ventures Ltd | Information & communication | 2024 |
| Albanian Court Management Limited | Households | 1994 |
| Albans Books Exchange Ltd | Wholesale & retail | 2021 |
| Albans Chimneys Limited | Administrative & support | 2022 |
| Albans Finance Limited | Professional & scientific | 2025 |
| Albanwood Engineering Services Ltd | Professional & scientific | 2026 |
| Albeny Gate Freehold Ltd | Households | 2025 |
| Albeny Gate Residents Company Ltd | Households | 2024 |
| Albert Stebbings Music Limited | Arts & recreation | 2020 |
| Albin Investments Limited | Administrative & support | 2003 |
| Albion Energy Trading Limited | Professional & scientific | 2016 |
| Albrox Limited | Financial services | 2015 |
| Albury DCL Ltd | Real estate | 2016 |
| Alchemist Property Limited | Real estate | 2018 |
| Alderson Digital Services Limited | Information & communication | 2020 |
| Alderstates Property Limited | Real estate | 2016 |
| Alee Management Services Ltd | Households | 2024 |
| Alero Group Ltd | Construction | 2024 |
| Aleviking Ltd | Construction | 2019 |
| Alex B HGV Ltd | Transport & logistics | 2022 |
| Alex Bauldry Limited | Real estate | 2023 |
| Alex Camacho Graphics Limited | Arts & recreation | 2013 |
| Alex Moody Associates Limited | Construction | 2011 |
| Alex Shrimpton Consulting Ltd | Professional & scientific | 2025 |
| Alexander Charles Limited | Construction | 2019 |
| Alexandra Square Management Company Limited | Households | 2001 |
| Alexandria Investments Limited | Real estate | 2025 |
| Alfarid (ST. Albans) Ltd | Hospitality | 2020 |
| Alga Zelda Ltd | Health & social care | 2022 |
| Algebra Winter Ltd | Information & communication | 2017 |
| Algodon Services Ltd | Information & communication | 2026 |
| ALI Ibrahim Associates Limited | Professional & scientific | 2023 |
| ALI Scott Ltd | Extraterritorial | 2025 |
| ALI Spice Ltd | Hospitality | 2025 |
| Alicorn IV (KNF I) LLP | | 2020 |
| Alicorn IV (KNF II) LLP | | 2020 |
| Align With Madi Ltd | Health & social care | 2024 |