| Athena Commercial Interiors Limited | Construction | 2023 |
| Athena Electrical & Construction Ltd | Real estate | 2004 |
| Athena Holdings Group Limited | Financial services | 2024 |
| Athena Logistics Limited | Other services | 2025 |
| Athena Mentors CIC | Education | 2025 |
| Athena Models Limited | Professional & scientific | 2025 |
| Athena Organisation Limited | Health & social care | 2015 |
| Athena Property NW Limited | Real estate | 2012 |
| Athenaeum Consulting Limited | Administrative & support | 2000 |
| Athene Secure Limited | Information & communication | 2017 |
| Atherston Holdings Ltd | Health & social care | 2025 |
| Atherstone Care Services Ltd | Health & social care | 2026 |
| Atherstone Housing Limited | Real estate | 2026 |
| Athex Consulting Ltd | Professional & scientific | 2024 |
| Athletes in the Zone Foundation CIC | Public administration | 2024 |
| Athletes in the Zone Limited | Education | 2022 |
| Athletic Boost Ltd | Manufacturing | 2018 |
| Athletic Midlands Academy CIC | Other services | 2022 |
| Athlex Sports Ltd | Wholesale & retail | 2022 |
| Athlex Supplies Ltd | Wholesale & retail | 2026 |
| Athol Masonic Buildings Limited | Real estate | 1936 |
| Athvika Private Ltd | Wholesale & retail | 2024 |
| Athwal & Dhaliwal Limited | Wholesale & retail | 2010 |
| Athwal Ltd | Real estate | 2025 |
| Athwal Properties Limited | Real estate | 2018 |
| Athwal Stores Limited | Wholesale & retail | 2025 |
| Athwari Projects Limited | Professional & scientific | 2018 |
| Athwas Ltd | Wholesale & retail | 2025 |
| Atia's Collection Ltd | Wholesale & retail | 2024 |
| Atif Consultants Limited | Health & social care | 2013 |
| Atif Investments Ltd | Real estate | 2025 |
| Atif Nexus Limited | Wholesale & retail | 2025 |
| Atif Sandhu Limited | Wholesale & retail | 2025 |
| Atif Sweets Ltd | Wholesale & retail | 2019 |
| Atif’S Delivery Service Ltd | Transport & logistics | 2025 |
| Atiq Construction Ltd | Construction | 2025 |
| Atish and Amber Properties Limited | Construction | 2024 |
| Atisons Group Ltd | Transport & logistics | 2025 |
| Atiyyah.Shop Ltd | Wholesale & retail | 2024 |
| ATK Investment Limited | Administrative & support | 2021 |
| Atkins Clarke Ltd | Administrative & support | 2023 |
| Atkins Estates Services Ltd | Real estate | 2024 |
| Atkins Gardening and Grounds Maintenance Ltd | Administrative & support | 2024 |
| Atkins Leisure Ltd | Hospitality | 2016 |
| Atkins TM Ltd | Construction | 2025 |
| Atlanta Motors Ltd | Wholesale & retail | 2022 |
| Atlantech Drives & Controls Limited | Wholesale & retail | 2017 |
| Atlantic Empire Ltd | Wholesale & retail | 2024 |
| Atlantic Engineering Solutions Limited | Information & communication | 2015 |
| Atlantic GBR Limited | Transport & logistics | 2026 |
| Atlantic House Group Limited | Financial services | 2015 |
| Atlantic House Holdings Limited | Financial services | 2021 |
| Atlantic House Investments Limited | Financial services | 2019 |
| Atlantic Joinery Services Limited | Manufacturing | 2000 |
| Atlantic Ocean Group Ltd | Wholesale & retail | 2025 |
| Atlantic Springs Consulting Ltd | Information & communication | 2012 |
| Atlantis 241 Limited | Administrative & support | 2024 |
| Atlantis Agent Line Ltd | Real estate | 2021 |
| Atlantis Education and Training Ltd | Education | 2024 |
| Atlantis Finance Limited | Financial services | 2025 |
| Atlantis Fish Bar Banbury Ltd Limited | Hospitality | 2025 |
| Atlantis Linen Services Ltd | Administrative & support | 2019 |
| Atlantis Modeling Agency Ltd | Professional & scientific | 2018 |
| Atlantis Money Box Ltd | Financial services | 2021 |
| Atlantis Mortgage Solutions Ltd | Extraterritorial | 2023 |
| Atlantis Translate Line Ltd | Professional & scientific | 2021 |
| Atlantis Travel Line Ltd | Administrative & support | 2021 |
| Atlantis Wasserbetten Limited | Professional & scientific | 2006 |
| Atlas 2 Limited | Wholesale & retail | 2026 |
| Atlas 2026 Bidco Limited | Financial services | 2026 |
| Atlas 2026 Holdco Limited | Financial services | 2026 |
| Atlas 2026 Midco Limited | Financial services | 2026 |
| Atlas 2026 Topco Limited | Financial services | 2026 |
| Atlas Acquisitions Group Ltd | Financial services | 2022 |
| Atlas Acre Ltd | Real estate | 2025 |
| Atlas Building Materials Ltd | Wholesale & retail | 2023 |
| Atlas Business Solutions Limited | Administrative & support | 2016 |
| Atlas Careers Ltd | Information & communication | 2023 |
| Atlas Commercial Finance Ltd | Financial services | 2026 |
| Atlas Escape Travel Ltd | Administrative & support | 2025 |
| Atlas Forte Ltd | Administrative & support | 2025 |
| Atlas FX Limited | Administrative & support | 2025 |
| Atlas GAS Heating and Plumbing Service Limited | Mining & quarrying | 2021 |
| Atlas Glazing Limited | Construction | 2018 |
| Atlas Group Operations Ltd | Financial services | 2026 |
| Atlas Logistics UK Holdings Limited | Financial services | 2024 |
| Atlas Logistics UK Limited | Transport & logistics | 2009 |
| Atlas Marketing Group Ltd | Wholesale & retail | 2026 |
| Atlas Mill RTM Company Ltd | Households | 2025 |
| Atlas Mini Market Ltd | Wholesale & retail | 2023 |
| Atlas MRC Ltd | Households | 2025 |
| Atlas Property Ltd | Real estate | 2021 |
| Atlas Property One Ltd | Real estate | 2024 |
| Atlas RE Limited | Real estate | 2021 |
| Atlas Solutions -UK Ltd | Administrative & support | 2025 |
| Atlas Solutions PTE Ltd | Professional & scientific | 2023 |
| Atlas Supply Group Ltd | Wholesale & retail | 2025 |
| Atlas Technology Group Ltd | Information & communication | 2019 |
| Atlas Youth Sports Club CIC | Arts & recreation | 2026 |
| Atlas@Co Limited | Wholesale & retail | 2025 |