| Alje Ltd | Administrative & support | 2016 |
| Alkan Takeaways Limited | Hospitality | 2018 |
| ALL Aspects Housing Ltd | Real estate | 2026 |
| ALL Aspects Services Ltd | Water & waste | 2025 |
| ALL Burgers Limited | Hospitality | 2013 |
| ALL Car Glass Ltd | Other services | 2019 |
| ALL Excelling Care and Education Limited | Public administration | 2025 |
| ALL Exquisite Stays Limited | Administrative & support | 2024 |
| ALL Garden Landscapes Ltd | Construction | 2025 |
| ALL in One Wholesale Ltd | Wholesale & retail | 2025 |
| ALL Island Construction Ltd | Manufacturing | 2021 |
| ALL Safe and Sound Limited | Information & communication | 2001 |
| ALL Sorts Enterprise Limited | Wholesale & retail | 2016 |
| ALL Special Foods Ltd | Hospitality | 2022 |
| ALL Style Ltd | Manufacturing | 2024 |
| ALL Talents Music School Limited | Education | 2017 |
| ALL Things Fashion CIC | Arts & recreation | 2025 |
| ALL Things Football Development Ltd | Arts & recreation | 2024 |
| ALL Time Building Ltd | Construction | 2016 |
| Alla Construction Ltd | Construction | 2020 |
| Allbrite Ltd | Real estate | 1998 |
| Allegiance Holdings Ltd | Real estate | 2021 |
| Alleluia Ministries UK Ltd | Health & social care | 2021 |
| Allen A.F. Cleaning & Removal Import & Export Services Ltd | Transport & logistics | 2021 |
| Allen Electrical Ltd | Administrative & support | 2015 |
| Alleyne Dance Ltd. | Arts & recreation | 2016 |
| Allfloors London Ltd | Construction | 2018 |
| Allie INT Ltd | Professional & scientific | 2022 |
| Allsorts of Clothing Company Limited | Wholesale & retail | 2025 |
| Alluring Beauty Limited | Wholesale & retail | 2023 |
| Allushi Properties Limited | Real estate | 2019 |
| Allyourproblemssolved Ltd | Transport & logistics | 2025 |
| Alma Crash Repairs Center Ltd | Wholesale & retail | 2018 |
| Alma Property Management Limited | Extraterritorial | 2004 |
| Alma Taxi Motor Ltd | Wholesale & retail | 2018 |
| Almatrix Digital Ltd | Information & communication | 2025 |
| Almux Ltd | Professional & scientific | 2020 |
| Alodia Advisory Limited | Professional & scientific | 2026 |
| Alonetiger Ltd | Transport & logistics | 2019 |
| Alor Bottles Limited | Wholesale & retail | 2017 |
| Alorsfaim Limited | Wholesale & retail | 2022 |
| Alpha & Brown Eagle Ltd | Hospitality | 2023 |
| Alpha Crew Ltd | Extraterritorial | 2012 |
| Alpha Crew Security Ltd | Administrative & support | 2023 |
| Alpha Global Group Ltd | Professional & scientific | 2019 |
| Alpha Global Holdings Ltd | Real estate | 2023 |
| Alpha Legacy Properties Ltd | Real estate | 2026 |
| Alpha Meats Ltd | Wholesale & retail | 2026 |
| Alpha Venue & Event People Ltd | Other services | 2012 |
| Alphabet Real Estate (Enfield) Limited | Real estate | 2024 |
| Alphabet Real Estate (Residential) Limited | Real estate | 2026 |
| Alphabet Real Estate Eastbourne Limited | Real estate | 2020 |
| Alphabet Real Estate Ltd | Real estate | 2019 |
| Alphatex Limited | Real estate | 2016 |
| Alpin Nordic Investment Limited | Manufacturing | 2023 |
| Alpine Rose Interiors Limited | Professional & scientific | 2019 |
| ALS Decor & Build Ltd | Construction | 2024 |
| ALS Property Care Ltd | Construction | 2026 |
| Altai Store Ltd | Wholesale & retail | 2025 |
| Altan Investment Ltd | Real estate | 2023 |
| Altaybridge Ltd | Wholesale & retail | 2025 |
| Alternative SUD Ltd | Mining & quarrying | 2025 |
| Alti Limited | Other services | 2016 |
| Altida Hire and Transport Ltd | Wholesale & retail | 2025 |
| Altin Falci GF Ltd | Other services | 2025 |
| Altitude Assets Limited | Real estate | 2015 |
| Altitude Contractors Limited | Construction | 2016 |
| Alto Cafe Ltd | Hospitality | 2025 |
| Alton Fashion Futures Community Interest Company | Education | 2025 |
| Altram Solutions Limited | Professional & scientific | 2015 |
| Altun Management Ltd | Real estate | 2025 |
| Altun Property Ltd | Real estate | 2024 |
| Altun Welding & Pipe Fitting Services Ltd | Construction | 2020 |
| Altuntas Plumbing & Heating Ltd | Construction | 2024 |
| Aluframes Direct Ltd | Manufacturing | 2019 |
| Alver Academy Ltd | Education | 2026 |
| Alver Acquisitions Ltd | Real estate | 2024 |
| Alvin Estates Ltd | Real estate | 2018 |
| Alvin MB Ltd | Construction | 2014 |
| Always EU & TU Ltd | Other services | 2018 |
| Alya London Ltd | Other services | 2023 |
| Alya Yagmur Ltd | Real estate | 2020 |
| Alykos Ltd | Administrative & support | 2023 |
| Alzz Music Ltd | Information & communication | 2022 |
| AM Brickwork Services Ltd | Construction | 2024 |
| AM Elite Smile Ltd | Health & social care | 2021 |
| AM Investment Properties Ltd | Real estate | 2019 |
| AM Property Services (S.E.) Ltd | Construction | 2015 |
| Am/Pm Studios Ltd | Information & communication | 2025 |
| Amadeus SAT Ltd | Information & communication | 2019 |
| Amadrop Ltd | Wholesale & retail | 2025 |
| Amaize Development Ltd | Professional & scientific | 2011 |
| Amaly Services (UK) Ltd | Construction | 2020 |
| Amalys Enterprises Limited | Wholesale & retail | 2021 |
| Amare Vita Clothing Ltd | Wholesale & retail | 2017 |
| Amaroo IT Ltd | Information & communication | 2023 |
| Amazed Gardening Transformation Ltd | Professional & scientific | 2022 |
| Amazement Limited | Hospitality | 2011 |
| Amazing Touch London Limited | Other services | 2019 |
| Amazon Building Construction Ltd | Construction | 2019 |