| Advent Plastics Limited | Manufacturing | 1959 |
| Adventure Fur-Ever Limited | Other services | 2022 |
| ADY Recovery Ltd | Construction | 2018 |
| Adzigo Holdings Limited | Professional & scientific | 2009 |
| AE Design & Surveying Services Ltd | Professional & scientific | 2023 |
| AF HR Ltd | Construction | 2020 |
| AF Property Ventures Ltd | Real estate | 2026 |
| AFC Digital Limited | Wholesale & retail | 2020 |
| AFC Solutions Ltd | Construction | 2026 |
| Afribean Ltd | Information & communication | 2017 |
| Afric Flavors CIC | Hospitality | 2024 |
| Africa Film Company Limited | Information & communication | 2019 |
| Afro Central Market Ltd | Hospitality | 2022 |
| Afro Seafood & Poultry Ltd | Wholesale & retail | 2023 |
| Afterlife Studios Ltd | Information & communication | 2015 |
| Agamar Houses Ltd | Real estate | 2020 |
| Agat Limited | Administrative & support | 2008 |
| AGD Services Ltd | Administrative & support | 2022 |
| Agege Ltd | Education | 2025 |
| Agnes James Ltd | Real estate | 2016 |
| AGR Retail Ltd | Wholesale & retail | 2021 |
| AGS Builders Limited | Construction | 2023 |
| Ahaa Ltd | Transport & logistics | 2020 |
| AHC Group Ltd | Information & communication | 2007 |
| AHC Hard & Software Ltd | Information & communication | 2007 |
| AHG Composites Ltd | Professional & scientific | 2016 |
| Ahskad Consultancy Ltd | Professional & scientific | 2018 |
| Aidan O'Reilly Consultancy Ltd | Financial services | 2017 |
| Ailerua Limited | Transport & logistics | 2023 |
| Aim-Roofing Ltd | Construction | 2023 |
| Ainos Properties Ltd | Real estate | 2022 |
| Ainsworth & Woodcock Engineering Ltd | Manufacturing | 2016 |
| Air CON First Ltd | Construction | 2023 |
| AIS Construct Ltd | Construction | 2026 |
| AJA Market Ltd | Wholesale & retail | 2026 |
| AJB Engineering Limited | Professional & scientific | 2022 |
| AJM Technologies Ltd | Manufacturing | 2024 |
| AK & Associates Ltd | Health & social care | 2023 |
| AK Alkins Estates Ltd | Real estate | 2025 |
| AK Fade NN9 Ltd | Other services | 2025 |
| AK Korang Limited | Health & social care | 2023 |
| AK Property Ventures Ltd | Real estate | 2021 |
| AK Stores Leicester Ltd | Wholesale & retail | 2020 |
| AK6 Group Ltd | Hospitality | 2023 |
| AK9 Properties Ltd | Real estate | 2024 |
| AKA Market Ltd | Wholesale & retail | 2024 |
| Akasunshine Limited | Wholesale & retail | 2024 |
| AKF Trading Ltd | Construction | 2024 |
| Akira Turk Network Logistics Ltd | Transport & logistics | 2025 |
| Akiti Limited | Manufacturing | 2020 |
| Akrg Holdings Ltd | Financial services | 2026 |
| AKS Multitrade Ltd | Construction | 2025 |
| Akwscaffolding Ltd | Construction | 2023 |
| AL Dente Club LLP | | 2025 |
| Alam Noor Ltd | Health & social care | 2017 |
| Alan & Gary Services Ltd | Construction | 2015 |
| Alan John Wood Limited | Administrative & support | 2010 |
| ALC Home Cakes Ltd | Manufacturing | 2024 |
| ALC Polo Limited | Administrative & support | 2017 |
| Alcoblock Ltd | Other services | 2021 |
| Aldarcare Ltd | Health & social care | 2015 |
| Alde International (UK) Limited | Manufacturing | 2008 |
| Aldo Construct Ltd | Construction | 2022 |
| Aldridge Homes Ltd | Real estate | 2024 |
| Alech Ltd | Construction | 2026 |
| Alert Fire Safety Services Limited | Public administration | 2020 |
| Alessia & Serena Ltd | Transport & logistics | 2015 |
| Alex 2014 Ltd | Transport & logistics | 2023 |
| Alex Carpentry Ltd | Construction | 2016 |
| Alex Cosmin Ltd | Wholesale & retail | 2025 |
| Alex Little Panel and Paint Limited | Wholesale & retail | 2016 |
| Alexaida Ltd | Transport & logistics | 2019 |
| Alexander Building and Consulting Ltd | Construction | 2014 |
| Alexander Equestrian Ltd | Wholesale & retail | 2025 |
| Alexpopa Ltd | Transport & logistics | 2019 |
| Algund Consultancy Services Limited | Administrative & support | 2018 |
| Alimteam Limited | Manufacturing | 1999 |
| Alix Travel Limited | Administrative & support | 2024 |
| ALL Angles Joinery and Display Limited | Manufacturing | 2016 |
| ALL Angles Storage Solutions Ltd | Transport & logistics | 2023 |
| ALL Aspect (Northants) Ltd | Construction | 2017 |
| ALL Aspects Holdings Ltd | Financial services | 2020 |
| ALL Aspects Tree Services Ltd. | Other services | 2015 |
| ALL County Maintenance Ltd | Other services | 2010 |
| ALL County Plastering Limited | Construction | 2023 |
| ALL for YOU - Singing Waiters Ltd | Arts & recreation | 2024 |
| ALL in Art Ltd | Wholesale & retail | 2026 |
| ALL Star Sports Teaching Ltd | Education | 2026 |
| ALL Time Consulting Ltd | Professional & scientific | 2024 |
| ALL Tree Aspects Ltd | Administrative & support | 2024 |
| All-Go Logistics Limited | Transport & logistics | 2022 |
| Allen, Everest and Associates Limited | Professional & scientific | 2015 |
| Alliance Commercial Mortgages Ltd | Financial services | 2019 |
| Alliance Mortgages Ltd | Financial services | 2018 |
| Alliance Property Service Agents Ltd | Real estate | 2018 |
| Allied Partner Ltd | Transport & logistics | 2018 |
| Allprint Display Ltd | Manufacturing | 2004 |
| Allsaints Healthcare - Integrated Care Group Limited | Professional & scientific | 2026 |
| ALM Technical Ltd | Professional & scientific | 2020 |
| Alma Street Car Wash Ltd | Administrative & support | 2026 |