| Aurora AI Ltd | Information & communication | 2025 |
| Aurora Golden Tech Ltd | Information & communication | 2025 |
| Aurumont Trading Ltd | Other services | 2021 |
| Ausomechoice Ltd | Wholesale & retail | 2021 |
| Aussienest Ltd | Wholesale & retail | 2023 |
| Austin-Grace Associates Limited | Other services | 2016 |
| Australis One Ltd | Wholesale & retail | 2024 |
| Ausumm Homes Limited | Construction | 2025 |
| Ausumm Investments Limited | Real estate | 2017 |
| Autex Parts Ltd | Wholesale & retail | 2020 |
| Authentic Burritos Ltd | Hospitality | 2025 |
| Auto Accident Claims Ltd. | Administrative & support | 2002 |
| Auto Damage UK Ltd | Other services | 2024 |
| Auto EX Machines Ltd | Wholesale & retail | 2025 |
| Auto Gearbox & DSG Specialist Ltd | Wholesale & retail | 2022 |
| Auto Giant Traders Limited | Wholesale & retail | 2018 |
| Auto LEO Ltd | Wholesale & retail | 2025 |
| Auto Midlands Ltd | Wholesale & retail | 2018 |
| Autoadmintools Ltd | Wholesale & retail | 2026 |
| Autocaveuk Ltd | Wholesale & retail | 2024 |
| Automate IT ALL Limited | Information & communication | 2026 |
| Automation Controls (PAK) Limited | Wholesale & retail | 2023 |
| Automoto Export Ltd | Wholesale & retail | 2010 |
| Autonize IT Limited | Information & communication | 2014 |
| Autopaints Repair Centre Limited | Wholesale & retail | 2018 |
| Autosupporta Ltd | Professional & scientific | 2026 |
| Autoval Ltd | Wholesale & retail | 2006 |
| Autovested Limited | Other services | 2020 |
| Autoxel Ltd | Wholesale & retail | 2025 |
| Auvora Ventures Ltd | Construction | 2025 |
| Auxano Properties Ltd | Real estate | 2025 |
| AV Joinery Ltd | Manufacturing | 2026 |
| AV Route Ltd | Transport & logistics | 2022 |
| AVA Special Projects Ltd | Construction | 2024 |
| Avamia Couture Limited | Wholesale & retail | 2019 |
| Avan Nails Ltd | Other services | 2022 |
| Avanted Ltd | Professional & scientific | 2025 |
| Avanti Consultancy Services Limited | Information & communication | 2010 |
| Avaria Accessories Ltd | Manufacturing | 2024 |
| AVB Home Ltd | Wholesale & retail | 2020 |
| AVD Expert Accounting Ltd | Professional & scientific | 2019 |
| AVD Expert Consulting Ltd | Professional & scientific | 2022 |
| Avel Interiors Ltd | Manufacturing | 2018 |
| Avelae Limited | Wholesale & retail | 2025 |
| Aveley Properties (West Thurrock) Limited | Construction | 1920 |
| Aveley Property Holdings Limited | Construction | 1996 |
| Aveley Washmill Limited | Construction | 2021 |
| Avenue & Park Lodge Residents Association Limited | Households | 1977 |
| Avenue Road Management Company (Harold Wood) Limited | Households | 2001 |
| Averex Ltd | Information & communication | 2013 |
| Avetik Limited | Real estate | 2019 |
| Avibid Limited | Health & social care | 2022 |
| Avimi Properties Ltd | Real estate | 2025 |
| Avin Tech Limited | Information & communication | 2013 |
| Avinox Ltd | Wholesale & retail | 2024 |
| Avision Carpentry Ltd | Manufacturing | 2018 |
| Avision Group Ltd | Construction | 2026 |
| Avitalle Services Ltd | Health & social care | 2010 |
| AVM Educational Ltd | Education | 2016 |
| Avmak Ltd | Professional & scientific | 2023 |
| AVN Transport Ltd | Transport & logistics | 2019 |
| Avocet Care Ltd | Wholesale & retail | 2009 |
| Avolyte Ltd | Wholesale & retail | 2024 |
| Avrus Development Limited | Construction | 2024 |
| AVS Associates Limited | Professional & scientific | 2019 |
| AVS Digital Ltd | Information & communication | 2024 |
| AVS Services Limited | Construction | 2017 |
| Avyukth Limited | Health & social care | 2019 |
| AW Facades Ltd | Construction | 2004 |
| AW Movie Production Ltd | Information & communication | 2022 |
| Awan Executive Travels Ltd | Transport & logistics | 2022 |
| Awan Store Limited | Wholesale & retail | 2022 |
| Awara KRD Ltd | Wholesale & retail | 2025 |
| Award Crafters Limited | Manufacturing | 1995 |
| Award Interiors Construction Limited | Construction | 2025 |
| Away Stays SA Ltd | Hospitality | 2021 |
| Awesome Dessert Ltd | Hospitality | 2019 |
| Awespitality Consultants Ltd | Hospitality | 2024 |
| AWH Property Ltd | Real estate | 2024 |
| AWH Roofing Limited | Construction | 2025 |
| AWK Plumbing Services Limited | Construction | 2026 |
| AX Carbon UK Ltd | Wholesale & retail | 2025 |
| Axarp Ltd | Real estate | 2022 |
| AXE Granite Limited | Construction | 2022 |
| Axiom Fire & Security Services Ltd | Administrative & support | 2026 |
| Axiom Observability Ltd | Information & communication | 2022 |
| Axis Growth Sales Ltd | Professional & scientific | 2026 |
| Axis Timber Construction Ltd | Construction | 2025 |
| Axium Limited | Information & communication | 2025 |
| Axle Automotive Limited | Wholesale & retail | 2023 |
| Axxess Ltd | Education | 2012 |
| AY7 Limited | Hospitality | 2025 |
| Ayaan & Adyan Medics Limited | Health & social care | 2015 |
| Ayaan Property Investment Ltd | Real estate | 2024 |
| Ayad KRD Ltd | Wholesale & retail | 2025 |
| Ayah Modesque Ltd | Wholesale & retail | 2022 |
| Ayan Motors Limited | Wholesale & retail | 2023 |
| Ayan&Co Ltd | Wholesale & retail | 2025 |
| Ayaz Tyres & Wheels Ltd | Wholesale & retail | 2019 |
| Ayconsult Ltd | Information & communication | 2025 |