| Arlinton 2000 Limited | Wholesale & retail | 2001 |
| Arlo XH Ltd | Hospitality | 2026 |
| Arman Grocery Ltd | Wholesale & retail | 2022 |
| Armchair Marketing Limited | Professional & scientific | 2016 |
| Armodias Ltd | Professional & scientific | 2023 |
| Armodias Services Limited | Professional & scientific | 2024 |
| Armoured Fire & Security Systems Ltd | Administrative & support | 2016 |
| Armstrong's Fulfilment & Warehousing Limited | Transport & logistics | 2024 |
| ARN Brothers Construction Ltd | Construction | 2025 |
| Arnas Transport Ltd | Transport & logistics | 2015 |
| Arnold Engineering Plastics Limited | Manufacturing | 1972 |
| Arnold Estates Limited | Construction | 1959 |
| Arnold Sign and Graphics Limited | Manufacturing | 1999 |
| Arnott Conveyors Limited | Manufacturing | 1995 |
| Arnott Handling Equipment Limited | Manufacturing | 2004 |
| Arnwood Limited | Real estate | 2014 |
| ARO Consulting Limited | Real estate | 2009 |
| Aroma of India (SRI SAI) Ltd | Hospitality | 2018 |
| Aron's Barber Shop Ltd | Other services | 2020 |
| Arpexas Ltd | Professional & scientific | 2005 |
| ARR Consultancy Ltd | Professional & scientific | 2026 |
| Arrav Property Solutions Limited | Real estate | 2020 |
| Arrdee Holdings Ltd | Financial services | 2021 |
| Arrdee Ltd | Arts & recreation | 2021 |
| Arridom Arsenal Investments Ltd | Real estate | 2023 |
| Arro Construction Ltd | Construction | 2026 |
| Arrow Edible Oils Ltd | Wholesale & retail | 2008 |
| Arrow Point Limited | Real estate | 2004 |
| Arrow Sight Optics Ltd | Manufacturing | 2025 |
| Arrow Surveys Limited | Professional & scientific | 2007 |
| Arrows Event Hire Limited | Administrative & support | 2022 |
| Arrowtech Hybrid Limited | Wholesale & retail | 2025 |
| ARS UK Food Limited | Hospitality | 2020 |
| ARS Vida Ltd | Real estate | 2025 |
| Arsham Catering Ltd | Hospitality | 2023 |
| Arslan Networks Limited | Wholesale & retail | 2025 |
| Arslan Ottoman Kitchen Limited | Hospitality | 2019 |
| Art Accommodation Ltd | Real estate | 2025 |
| Art Construct 88 Limited | Construction | 2025 |
| Art Expressions Ltd | Information & communication | 2023 |
| Art Expressions UK Community Interest Company | Arts & recreation | 2025 |
| Art From A&K Limited | Arts & recreation | 2019 |
| Art History Lite Ltd | Wholesale & retail | 2024 |
| Art Invest Tour Ltd | Transport & logistics | 2017 |
| Art Investments (Lancaster) Limited | Hospitality | 2022 |
| Art Music Gallery (UK) Limited | Manufacturing | 2012 |
| Art of the Soul Ltd | Arts & recreation | 2023 |
| Art Stone Properties Ltd | Financial services | 2026 |
| Artcladd Ltd | Construction | 2023 |
| Arte Globale Limited | Wholesale & retail | 2014 |
| Artec Enterprises Limited | Other services | 2022 |
| Artemis Adjusting Limited | Financial services | 2017 |
| Artemis Building Services Ltd | Construction | 2014 |
| Artemis Contracting Ltd | Construction | 2026 |
| Artemis Foods Limited | Wholesale & retail | 2016 |
| Artemis Group Holdings Limited | Other services | 2007 |
| Artesian Holdings Ltd | Real estate | 2016 |
| Arthouse Creative Limited | Education | 2026 |
| Arthouse Northampton Limited | Wholesale & retail | 2024 |
| Arthur Day Composites Ltd | Manufacturing | 2024 |
| Arthur Street Management (Wellingborough) Limited | Households | 2011 |
| Arthur Trans Limited | Transport & logistics | 2016 |
| Arthurrooms Ltd | Real estate | 2020 |
| Arthurs Veterinary Specialists Limited | Professional & scientific | 2019 |
| Arti-Pat Ltd | Wholesale & retail | 2021 |
| Artibor Ltd | Transport & logistics | 2022 |
| Artic Events Limited | Hospitality | 2022 |
| Article Clothing Ltd | Wholesale & retail | 2025 |
| Artikas Ltd | Transport & logistics | 2022 |
| Artisan 786 Alleys Ltd | Information & communication | 2024 |
| Artisan Care Clevedon Limited | Health & social care | 2017 |
| Artisan Care Downham Limited | Health & social care | 2022 |
| Artisan Care Godmanchester Limited | Health & social care | 2021 |
| Artisan Care Group Limited | Financial services | 2021 |
| Artisan Care Holdco Limited | Professional & scientific | 2017 |
| Artisan Care Kettering Limited | Health & social care | 2018 |
| Artisan Care Northampton Limited | Health & social care | 2020 |
| Artisan Care Northants Holdco Limited | Professional & scientific | 2009 |
| Artisan Care Northants Limited | Health & social care | 2010 |
| Artisan Care Norwich Limited | Health & social care | 2020 |
| Artisan Care Sheringham Limited | Health & social care | 2022 |
| Artisan Contracts Limited | Construction | 2019 |
| Artisan Factory Ltd | Health & social care | 2022 |
| Artisan IVY Holdco Limited | Financial services | 2021 |
| Artisan IVY Opco Limited | Health & social care | 2021 |
| Artisan Medical Ltd | Health & social care | 2021 |
| Artisan Oak Ltd | Construction | 2020 |
| Artisan Project Management Ltd | Professional & scientific | 2024 |
| Artisan Tools Limited | Wholesale & retail | 1981 |
| Artisan UK Holdings Limited | Financial services | 2024 |
| Artisan UK Property Limited | Real estate | 2024 |
| Artisans Outsourcing Solutions Ltd | Professional & scientific | 2021 |
| Artisiam Limited | Information & communication | 2000 |
| Artistry Roofing Ltd | Construction | 2019 |
| Artistry Services Ltd | Health & social care | 2020 |
| Artizan Developments Limited | Real estate | 2018 |
| Artizan Road (Northampton) Resident Management Group Limited | Households | 2025 |
| Artizan Roofing Services Ltd | Construction | 2025 |
| Artmustfare Ltd | Arts & recreation | 2016 |
| Arts Quarter LLP | | 2008 |