| Ackhurst Investments Limited | Financial services | 2018 |
| Ackor Ltd | Professional & scientific | 2026 |
| ACL Electrical North West Limited | Manufacturing | 2012 |
| ACL Industrial Flooring (ACL) Limited | Construction | 2017 |
| ACL Resin Flooring Limited | Construction | 2025 |
| Acland Bracewell Limited | Real estate | 1987 |
| Acorn Construction (London) Limited | Construction | 2005 |
| ACP Textile (UK) Limited | Wholesale & retail | 2013 |
| Acqua Systems Design Ltd | Construction | 2022 |
| Acqua Systems Plumbing Ltd | Construction | 2022 |
| ACS Bodyworks Ltd | Wholesale & retail | 2019 |
| ACS Heating and Plumbing Ltd | Construction | 2011 |
| Active Hvac Ltd | Construction | 2008 |
| Active Pathways Group Ltd | Health & social care | 2024 |
| Active Pathways Holdings Limited | Professional & scientific | 2014 |
| Active Pathways Limited | Health & social care | 2003 |
| Active Pathways Supported Living Ltd | Health & social care | 2019 |
| Acton Place Ltd | Real estate | 2026 |
| Acumen Concept Services Ltd | Agriculture & fishing | 2011 |
| Acura Build Limited | Construction | 2013 |
| Acute Recruit Ltd | Extraterritorial | 2021 |
| ACZ Associates Limited | Professional & scientific | 2018 |
| AD Blueprint Ltd | Real estate | 2025 |
| AD External Designs Ltd | Construction | 2026 |
| AD Housing Limited | Real estate | 2024 |
| AD Project Managament and Consulting Ltd | Professional & scientific | 2025 |
| AD Wise Media Limited | Professional & scientific | 2023 |
| Ad-Vance Controls Ltd | Professional & scientific | 2024 |
| Adam Brickson Ltd | Construction | 2024 |
| Adam French Joinery Limited | Construction | 2013 |
| Adam Holmes Limited | Information & communication | 2023 |
| Adam Logistics Limited | Transport & logistics | 2005 |
| Adam Michaels Group Ltd | Manufacturing | 2018 |
| Adamo Limited | Real estate | 2025 |
| Adaptable Access Bathrooms Ltd | Construction | 2021 |
| ADC Fire and Security Ltd | Administrative & support | 2013 |
| Addition Media Ltd | Professional & scientific | 2019 |
| Adglobalapp Ltd | Transport & logistics | 2023 |
| Adhd Inspired Limited | Health & social care | 2019 |
| Adhd Lancashire Ltd | Health & social care | 2023 |
| Adil Chohan Ltd | Financial services | 2016 |
| ADL Electrical Contractors Limited | Construction | 2023 |
| Adlington and District Carnival Committee Limited | Other services | 1989 |
| Adlington Car Care Limited | Wholesale & retail | 2021 |
| Adlington Catering Ltd | Hospitality | 2025 |
| Adlington Interior Finishes Limited | Construction | 2016 |
| Adlington Law Limited | Professional & scientific | 2011 |
| Adlington News Limited | Wholesale & retail | 2010 |
| Adlington Pet Centre Limited | Wholesale & retail | 2005 |
| Adlington Property Holdings Limited | Real estate | 2021 |
| Adlington Spice NW Ltd | Hospitality | 2024 |
| Adlington Welding Supplies Limited | Wholesale & retail | 1973 |
| Adnix UK Limited | Administrative & support | 2008 |
| ADP Ceilings Limited | Construction | 2006 |
| Adrian Barratt Swfp Limited | Financial services | 2007 |
| Adrian Mirzea Ltd | Construction | 2019 |
| Adroit Care Team (ACT) Limited | Health & social care | 2020 |
| ADS Commercial Services Ltd | Professional & scientific | 2017 |
| ADS Holding Group Ltd | Financial services | 2026 |
| Adtl Services Ltd | Wholesale & retail | 2016 |
| Advance Land & Property Sourcing Limited | Real estate | 2020 |
| Advance Link Group Limited | Administrative & support | 2003 |
| Advance Machining Solutions Ltd | Manufacturing | 2012 |
| Advance Tech (UK) Ltd | Information & communication | 2010 |
| Advanced Admixtures Limited | Manufacturing | 1989 |
| Advanced Child Care Assessments Limited | Health & social care | 2005 |
| Advanced Commercial Ltd | Transport & logistics | 2016 |
| Advanced Heating Systems Ltd | Information & communication | 1994 |
| Advanna Ltd | Manufacturing | 2026 |
| Advantage Virtual Agency Limited | Professional & scientific | 2021 |
| Advantage Virtual Assistants Limited | Professional & scientific | 2021 |
| Adviserally Limited | Information & communication | 2026 |
| Adwan Limited | Health & social care | 2021 |
| AE Property North West Ltd | Real estate | 2015 |
| AEG Garden Maintenance Ltd | Households | 2019 |
| Aegis Homes (Bright) Ltd | Health & social care | 2019 |
| AEM Preston Ltd | Real estate | 2023 |
| Aeonofenlightenment Ltd | Transport & logistics | 2019 |
| Aero Building Systems Ltd | Construction | 2002 |
| Aeron Training and Healthcare Education Ltd | Education | 2023 |
| Aerosol Industries Ltd | Manufacturing | 2019 |
| Aerospace & Engineering Tools Limited | Manufacturing | 2004 |
| Aerost Limited | Professional & scientific | 2019 |
| Aeroval Design Ltd | Professional & scientific | 2023 |
| AES Surgical Ltd | Health & social care | 2025 |
| Aesthetics Alliance Limited | Health & social care | 2025 |
| Aesthetics by Melissa Ltd | Health & social care | 2022 |
| Aesthetics Maison Limited | Other services | 2025 |
| Aevata Ltd | Information & communication | 2025 |
| AF Electrical Installation Ltd | Manufacturing | 2023 |
| AFB Recovery Ltd | Wholesale & retail | 2024 |
| AFG Health Ltd | Health & social care | 2023 |
| AFI Systems UK Ltd | Manufacturing | 2024 |
| AFR Healthcare Ltd | Health & social care | 2022 |
| AG Transportation Ltd | Transport & logistics | 2020 |
| AG4 Property Limited | Real estate | 2025 |
| AGE Support Limited | Administrative & support | 2025 |
| Agency Xpert Ltd | Professional & scientific | 2025 |
| Agenda Projects Limited | Professional & scientific | 2005 |
| Aggregate Commercial Limited | Professional & scientific | 2026 |