| Armour Daily Ltd | Wholesale & retail | 2025 |
| Armour Engineering Services Limited | Professional & scientific | 2022 |
| Armourshield General Services Ltd | Construction | 2024 |
| Armourshield Limited | Public administration | 2022 |
| Armourshield Roofing Services Ltd | Construction | 2024 |
| Arms Locked Alliance Ltd | Financial services | 2025 |
| Armsa Limited | Professional & scientific | 1999 |
| Armstrong Commercial Solutions Limited | Professional & scientific | 2016 |
| Armstrong Fluid Technology Limited | Extraterritorial | 2013 |
| Armstrong Holden Brooke Pullen Limited | Extraterritorial | 2010 |
| Armstrong Integrated Limited | Manufacturing | 2003 |
| Armstrong Integrated Systems Limited | Manufacturing | 2004 |
| Armstrong Pumps Limited | Manufacturing | 1977 |
| Armstrong Quay Freehold (Liverpool) Limited | Real estate | 2010 |
| Armstrong Quay Management Company (Liverpool) Limited | Real estate | 2004 |
| Armstrong Security Services (North-West) Limited | | 1985 |
| Armstrong Works Limited | Education | 2003 |
| Armstrongadams Limited | Information & communication | 2001 |
| Armt Estates Ltd | Real estate | 2025 |
| Armus Ltd | Information & communication | 2009 |
| Armykit UK Ltd | Wholesale & retail | 2025 |
| Armz Trainz Ltd | Arts & recreation | 2025 |
| Armée Ltd | Wholesale & retail | 2025 |
| ARN Events Limited | Wholesale & retail | 2023 |
| ARN Financial Services Ltd | Financial services | 2026 |
| ARN Limited | Hospitality | 2020 |
| Arnan Limited | Health & social care | 2021 |
| Arncliffe Living Ventures Ltd | Hospitality | 2024 |
| Arndale Catering Ltd | Hospitality | 2024 |
| Arndale Enterprise Limited | Wholesale & retail | 2022 |
| Arndale News Ltd | Wholesale & retail | 2018 |
| Arndale Star Nails and Beauty Ltd | Other services | 2023 |
| Arneb Ltd | Real estate | 2020 |
| Arnero Limited | Hospitality | 2014 |
| Arnest Properties Ltd | Construction | 2023 |
| Arnfield FLY Fishery Limited | Agriculture & fishing | 1993 |
| Arnold Stansby & Co. Limited | Financial services | 2011 |
| Arnold Stansby Holdings Limited | Financial services | 2012 |
| Aro's Paving Ltd | Other services | 2026 |
| Arobosta Limited | Manufacturing | 2024 |
| Arokaya Thai Yoga Massage & Spa Ltd | Other services | 2014 |
| Aroma Coffee House Ltd | Wholesale & retail | 2023 |
| Aroma Pizzeria Limited | Hospitality | 2021 |
| Aroma Quee Ltd | Wholesale & retail | 2022 |
| Aroma Quick Stop Ltd | Wholesale & retail | 2024 |
| Aroma Ristorante Ltd | Hospitality | 2025 |
| Aroma Suppliers Ltd | Wholesale & retail | 2025 |
| AROMA786 Ltd | Hospitality | 2023 |
| Aromas Flavourtech UK Ltd | Extraterritorial | 2020 |
| Aromathai Spa Ltd | Other services | 2012 |
| Aromatherapy Infusions Ltd | Wholesale & retail | 2015 |
| Arooj Healthcare Ltd | Wholesale & retail | 2026 |
| Arooj Properties Ltd | Real estate | 2024 |
| Arosa Trading Limited | Hospitality | 2024 |
| Aroscent Ltd | Wholesale & retail | 2025 |
| Arosh Corporation Limited | Wholesale & retail | 2021 |
| Around the World Logistics Ltd | Transport & logistics | 2019 |
| Around the Wurld Ltd | Hospitality | 2025 |
| Arovia Estates Ltd | Real estate | 2025 |
| Aroxer Ltd | Wholesale & retail | 2025 |
| Aroy Candles Limited | Wholesale & retail | 2026 |
| Aroza Estates Limited | Financial services | 2025 |
| ARP Grantham 1 Ltd | Extraterritorial | 2021 |
| ARP Grantham 2 Ltd | Extraterritorial | 2021 |
| ARP Homes Ltd | Households | 2025 |
| ARP Refurbishments Specialist Ltd | Construction | 2021 |
| Arpley Street Developments Limited | Households | 2022 |
| Arpuro Ltd | Administrative & support | 2025 |
| Arqelion Ltd | Wholesale & retail | 2026 |
| Arqilab Ltd | Construction | 2024 |
| Arra Collective Ltd | Wholesale & retail | 2024 |
| Arra Properties Ltd | Real estate | 2025 |
| Arrahman Funeral Services Ltd | Other services | 2021 |
| Arrasel Ltd | Construction | 2023 |
| Arrathorne Properties Limited | Real estate | 1970 |
| Array Ltd | Information & communication | 2019 |
| Array Trading Ltd | Wholesale & retail | 2021 |
| Arrecoverymcr Ltd | Transport & logistics | 2026 |
| Arrends Solutions Limited | Real estate | 2020 |
| Arrino Properties Ltd | Real estate | 2020 |
| Arrival Avenue Ltd | Administrative & support | 2025 |
| Arrival Services Limited | Administrative & support | 2017 |
| ARRIVE2DRIVE Limited | Transport & logistics | 2017 |
| Arrk Group Limited | Extraterritorial | 2004 |
| Arrk Limited | Information & communication | 1998 |
| Arrk Media Limited | Information & communication | 2017 |
| Arrow Cabs Tameside Limited | Transport & logistics | 2006 |
| Arrow Direct Ltd | Administrative & support | 1997 |
| Arrow Film & Foil Converters Limited | Manufacturing | 2012 |
| Arrow Finance Ltd | Professional & scientific | 2013 |
| Arrow Global (Holdings) Limited | Professional & scientific | 2005 |
| Arrow Global Accounts Management Limited | Financial services | 2005 |
| Arrow Global Adviser Limited | Other services | 2019 |
| Arrow Global Birch Holdings Limited | Financial services | 2022 |
| Arrow Global Europe Limited | Financial services | 2014 |
| Arrow Global European Service Company Limited | Financial services | 2022 |
| Arrow Global Group Limited | Financial services | 2013 |
| Arrow Global Investments Holdings Limited | Financial services | 2008 |
| Arrow Global Limited | Other services | 2005 |
| Arrow Global Luna Limited | Financial services | 2014 |