| Aaroo Associates Ltd | Information & communication | 2010 |
| Aarya Medical Ltd | Health & social care | 2012 |
| Aaseem Limited | Health & social care | 2015 |
| AB & Co Housing Ltd | Real estate | 2025 |
| AB Air Conditioning Services Ltd | Energy | 2025 |
| AB Property Holdings Limited | Real estate | 2020 |
| AB Sweets Ltd | Wholesale & retail | 2026 |
| Abacad Limited | Professional & scientific | 2005 |
| Abacus Cash Registers Limited | Manufacturing | 1999 |
| Abbey Funeral Service Ltd. | Extraterritorial | 1990 |
| Abbotwell Limited | Real estate | 2021 |
| ABC Leisure Events Ltd | Administrative & support | 2021 |
| Abcb Properties Limited | Real estate | 2025 |
| Abeera's Trading Limited | Wholesale & retail | 2019 |
| Aberford Limited | Transport & logistics | 2017 |
| ABF Systems Ltd | Information & communication | 2019 |
| ABG Consult Limited | Professional & scientific | 2015 |
| Abhay Ltd | Professional & scientific | 2014 |
| Abit Limited | Information & communication | 2013 |
| Abnd Limited | Hospitality | 2025 |
| Abode Living Lettings Limited | Real estate | 2017 |
| Abodes Group Limited | Real estate | 2018 |
| Above the Bolt Ltd | Professional & scientific | 2026 |
| ABS Abbey Building Services Limited | Construction | 2013 |
| ABS Designs Consulting Ltd | Professional & scientific | 2022 |
| ABS GAS & Plumbing Ltd | Construction | 2023 |
| Absr Holdings Limited | Financial services | 1998 |
| Acacia Family Support | Health & social care | 2007 |
| Academy Transformation Trust | Education | 2011 |
| Access Painting Investments Ltd | Construction | 2019 |
| Access Painting Ltd | Construction | 2015 |
| Accident Time Limited | Administrative & support | 2008 |
| Acclaim Housing Services Ltd | Real estate | 2025 |
| Accles & Shelvoke Limited | Manufacturing | 1927 |
| Accurafin Limited | Professional & scientific | 2014 |
| Acds Consultants Limited | Professional & scientific | 2005 |
| Acds Investments Limited | Real estate | 2025 |
| Ace Aesthetics Ltd | Administrative & support | 2017 |
| Ace Earth Solutions Ltd | Construction | 2020 |
| Ace Food Solutions Ltd | Professional & scientific | 2024 |
| Ace Holdings Midlands Limited | Financial services | 2025 |
| Ace Hospitality Ltd. | Hospitality | 2008 |
| Ace Superstore Ltd | Wholesale & retail | 2023 |
| Acepay Limited | Health & social care | 1989 |
| Acer Medical Consultant Limited | Health & social care | 2022 |
| ACH Thermoco Ltd | Professional & scientific | 2008 |
| Achi Investments Limited | Real estate | 2025 |
| ACK Bakery Ltd | Wholesale & retail | 2024 |
| ACK Supermarket Ltd | Wholesale & retail | 2024 |
| Acloud Solutions Limited | Information & communication | 2025 |
| ACM Scaffolding Limited | Construction | 2019 |
| Acme Engineering Products UK Limited | Manufacturing | 2016 |
| Acorn Birth Services Limited | Health & social care | 2013 |
| Acorn Country Capital Ltd | Financial services | 2006 |
| Acorn Tech Limited | Information & communication | 2023 |
| Acorns Day Nursery and Pre-School Ltd | Education | 2024 |
| Acquisition Works Limited | Professional & scientific | 2026 |
| ACRE2TWENTY Limited | Construction | 2012 |
| Acreiq Ltd | Information & communication | 2026 |
| Acren Limited | Health & social care | 2011 |
| Acres Estate Agents Limited | Professional & scientific | 2015 |
| Acres Financial Services Limited | Financial services | 2021 |
| Acres Residential Lettings Limited | Households | 2024 |
| Acres Sutton Coldfield Limited | Real estate | 2015 |
| Acrux Solutions Limited | Administrative & support | 2014 |
| ACS Financial Planning Limited | Financial services | 2011 |
| ACS Technical Services Limited | Construction | 2018 |
| ACT (Midlands) Limited | Real estate | 1986 |
| ACT Studios Limited | Professional & scientific | 2015 |
| Acten Limited | Construction | 2005 |
| Action Figures Limited | Wholesale & retail | 2024 |
| Active Media Print Services Limited | Information & communication | 2003 |
| Active NRG Ltd | Arts & recreation | 2025 |
| Activebodyhealthymind Ltd | Arts & recreation | 2017 |
| Acton Brands Limited | Professional & scientific | 2020 |
| Acton LEA Developments Limited | Construction | 2021 |
| Acuda Medicare Limited | Health & social care | 2021 |
| Acuitis Optical & Hearing Exeter Limited | Wholesale & retail | 2020 |
| Acuitis Optical & Hearing Limited | Wholesale & retail | 2016 |
| ACW Enterprises Limited | Real estate | 2026 |
| AD Machine Services Ltd | Manufacturing | 2017 |
| AD Rehab Ltd | Information & communication | 2026 |
| Adam & Rahman Legal Services Limited | Administrative & support | 2017 |
| Adam's Bay Limited | Hospitality | 2017 |
| Adana Turkish Barber Ltd | Other services | 2023 |
| Adaska Group Ltd | Real estate | 2022 |
| Adbuilder Holdings Ltd | Information & communication | 2019 |
| ADC Accountancy Limited | Professional & scientific | 2012 |
| Added Care Ltd | Health & social care | 2020 |
| Addictive Fitness Events Limited | Arts & recreation | 2025 |
| Addictive Fitness Limited | Arts & recreation | 2020 |
| Addison Consulting Limited | Professional & scientific | 2016 |
| Adela Funeral Homes Limited | Extraterritorial | 1981 |
| Adept Group (UK) Limited | Professional & scientific | 2011 |
| Adeska Investments Ltd | Real estate | 2018 |
| Adeska Ltd | Real estate | 2017 |
| Adhd Residential Training Limited | Health & social care | 2026 |
| Adhesive Supply Company Ltd | Manufacturing | 2016 |
| Adhoc Services Limited | Construction | 2009 |
| ADI Maintenance Limited | Water & waste | 2023 |