| Autotec Hire Bolton Limited | Administrative & support | 2025 |
| Autotecniq Limited | Wholesale & retail | 2025 |
| Autovag Limited | Wholesale & retail | 2013 |
| Autoware UK Ltd | Wholesale & retail | 2017 |
| Autowerks Limited | Wholesale & retail | 2015 |
| Auvien Limited | Administrative & support | 2018 |
| AV Fire Solutions Ltd | Public administration | 2026 |
| AV Price Ltd | Education | 2021 |
| AV Social Work Ltd | Health & social care | 2022 |
| AV Unibrak Midlands Limited | Construction | 2017 |
| AV Unibrak North Limited | Construction | 2017 |
| AVA (Merseyside) Limited | Other services | 2013 |
| AVA Care Liverpool Ltd | Health & social care | 2015 |
| AVA Skip Hire Limited | Water & waste | 2022 |
| Avaderma Ltd | Other services | 2021 |
| Avala (UK) Limited | Information & communication | 2012 |
| Avalily Ltd | Other services | 2020 |
| Avalon Debt Limited | Administrative & support | 2020 |
| Avalon Global Consulting Limited | Professional & scientific | 2020 |
| Avalon Hair Ltd | Other services | 2025 |
| Avant Financial Ltd | Other services | 2017 |
| Avant Investments Ltd | Financial services | 2017 |
| Avebury Estates Limited | Real estate | 2004 |
| Aventus 21 Limited | Wholesale & retail | 2021 |
| Aventus MD Holdings Limited | Financial services | 2022 |
| Averroes Holdings Limited | Real estate | 2019 |
| Avestan Healthcare Ltd | Wholesale & retail | 2023 |
| Avian Parking Limited | Transport & logistics | 2026 |
| Aviba Ltd | Transport & logistics | 2024 |
| Avicara Health Ltd | Health & social care | 2025 |
| Avid Agency Ltd | Professional & scientific | 2023 |
| Avid Interiors Ltd | Construction | 2025 |
| Avita Legal Limited | Professional & scientific | 2022 |
| AVJ Medical Ltd | Health & social care | 2025 |
| AVK Property Investments Limited | Real estate | 2019 |
| AVL Taverns Ltd | Hospitality | 2019 |
| Avlaki Limited | Manufacturing | 2014 |
| AVM Drylining Ltd | Construction | 2023 |
| AVM Solutions (UK) Ltd | Professional & scientific | 2012 |
| Avolgere Limited | Construction | 2024 |
| Avolve IT Limited | Information & communication | 2025 |
| Avon Electrical Services (NW) Limited | Construction | 2014 |
| Avon Technical Ltd | Professional & scientific | 2024 |
| Avonbridge Advisory Limited | Professional & scientific | 2024 |
| AVR Transcription Limited | Professional & scientific | 2003 |
| Avra Healthcare Limited | Manufacturing | 2020 |
| Avrenbridge Limited | | 1978 |
| Avtaxistravel Limited | Transport & logistics | 2024 |
| AW Childcare Services Ltd | Education | 2010 |
| AW Creative Holdings Ltd | Arts & recreation | 2025 |
| AW Electrical Contracting Ltd | Construction | 2021 |
| AW Marketing (Aware) Limited | Professional & scientific | 2010 |
| AW Mobile Limited | Wholesale & retail | 2020 |
| Awab Textiles Limited | Manufacturing | 2025 |
| Awabins Limited | Wholesale & retail | 2025 |
| Awaebbizs Ltd | Wholesale & retail | 2024 |
| Awaebbus Ltd | Wholesale & retail | 2024 |
| Awais Healthcare Limited | Health & social care | 2017 |
| Awaiz Innovations Ltd | Information & communication | 2026 |
| Awakeverse Ltd | Information & communication | 2025 |
| Awda Ltd | Health & social care | 2022 |
| AWE Sales Limited | Wholesale & retail | 2026 |
| Awesome Lettings Limited | Real estate | 2019 |
| AWK Engineering Ltd | Construction | 2024 |
| Awkcomputers Limited | Information & communication | 2005 |
| AWN Building Contractors Ltd | Construction | 2018 |
| Awonikar Limited | Wholesale & retail | 2024 |
| AWP Investments Ltd | Real estate | 2024 |
| Awsk Logistics Ltd | Transport & logistics | 2022 |
| Awsn Capital Limited | Professional & scientific | 2026 |
| AWT International Limited | Manufacturing | 2016 |
| AXD Environmental Limited | Manufacturing | 2015 |
| AXD Holdings Ltd | Financial services | 2026 |
| AXE CAP Estate Ltd | Real estate | 2026 |
| Axford Transmissions Ltd | Wholesale & retail | 2021 |
| Axial Exploration and Drilling Supplies Ltd | Wholesale & retail | 2021 |
| Axiiom Limited | Professional & scientific | 2024 |
| Axiomconsultingai Ltd | Professional & scientific | 2025 |
| Axios Holdings Ltd | Information & communication | 2025 |
| Axis Point Limited | Wholesale & retail | 2025 |
| Axis Project Services Ltd | Construction | 2025 |
| Axis Security Training Limited | Administrative & support | 2011 |
| Axis Vehicle Solutions Limited | Wholesale & retail | 2025 |
| Axiy Limited | Real estate | 2025 |
| AXP Accountancy Limited | Professional & scientific | 2012 |
| AY Accountants LLP | | 2018 |
| AY Digital Solutions Ltd | Professional & scientific | 2025 |
| AY Technologies Limited | Wholesale & retail | 2026 |
| AY-23 Ltd | Wholesale & retail | 2025 |
| AY12 Ltd | Professional & scientific | 2021 |
| Ayaleena Properties Ltd | Real estate | 2018 |
| Ayat Hussein Optics Ltd | Health & social care | 2023 |
| AYD Logistics Ltd | Transport & logistics | 2025 |
| Ayesha Qaiser Ltd | Wholesale & retail | 2025 |
| Aylaf Haulage Ltd | Transport & logistics | 2021 |
| AYM Optics Ltd | Health & social care | 2014 |
| Aymad Group Ltd | Wholesale & retail | 2025 |
| Ayod Consulting Limited | Information & communication | 2019 |
| AYR Goods Limited | Wholesale & retail | 2023 |
| Ayraskon Limited | Wholesale & retail | 2025 |