| ACG Broking Services Limited | Professional & scientific | 2019 |
| ACG Courier Ltd | Transport & logistics | 2026 |
| ACG Mediterranean Limited | Professional & scientific | 2005 |
| Acharya Aerospace Ltd | Wholesale & retail | 2024 |
| Achieve Events Ltd | Administrative & support | 2019 |
| Achilles Takeaway Limited | Hospitality | 2024 |
| Achlan Global Limited | Professional & scientific | 2022 |
| Acib Holdings Limited | Financial services | 2024 |
| Acix Systems Limited | Manufacturing | 2025 |
| ACJ Leisure Limited | Hospitality | 2018 |
| ACJ Property Developments Limited | Construction | 2014 |
| ACJ Transport Ltd | Transport & logistics | 2020 |
| Ackroyd Construction Limited | Construction | 2025 |
| Ackroyd Group Holdings Ltd | Financial services | 2025 |
| Ackroyd Group Properties Ltd | Real estate | 2025 |
| Ackroyd Transport Ltd | Transport & logistics | 2002 |
| Acks Global Limited | Administrative & support | 2018 |
| ACL Gilchrist Ltd | Professional & scientific | 2020 |
| Acleanerclean Ltd | Administrative & support | 2025 |
| Acnum Ltd | Transport & logistics | 2024 |
| ACO Properties Ltd | Real estate | 2023 |
| Acoglobal Ltd | Information & communication | 2025 |
| Acop Inspection Services Ltd | Professional & scientific | 2017 |
| Acorn Accountancy Limited | Professional & scientific | 2010 |
| Acorn Conceptual Textiles Ltd | Manufacturing | 2005 |
| Acorn Connect Ltd | Administrative & support | 2020 |
| Acorn Equity Ltd | Real estate | 2020 |
| Acorn Estates (Giltbrook) Management Company Limited | Households | 2019 |
| Acorn HR Consultancy Limited | Administrative & support | 2015 |
| Acorn Lifting Limited | Construction | 2024 |
| Acorn Lifting Services Limited | Construction | 2025 |
| Acorn Properties Nottingham Limited | Real estate | 2017 |
| Acorn Property Management (EM) Ltd | Real estate | 2022 |
| Acorn Travel (UK) Ltd | Transport & logistics | 2022 |
| Acorn Tree Services Nottingham Limited | Administrative & support | 2016 |
| Acorn Windows (Nottingham) Limited | Construction | 1994 |
| Acourt Investments Ltd | Real estate | 2018 |
| Acourt Properties Ltd | Real estate | 2026 |
| Acoustickle CIC | Arts & recreation | 2025 |
| ACP (NO 4) Limited | Financial services | 2019 |
| ACP (NO 5) Ltd | Administrative & support | 2019 |
| ACP (NO1) Limited | Financial services | 2017 |
| ACP (NO2) Limited | Financial services | 2017 |
| ACP (NO3) Limited | Administrative & support | 2019 |
| Acqua Consultancy Ltd | Professional & scientific | 2024 |
| Acqua Group Limited | Professional & scientific | 2024 |
| Acqukanos PVT Ltd Limited | Health & social care | 2014 |
| Acrane Ltd | Administrative & support | 2017 |
| Acreline Properties Ltd | Households | 2025 |
| Acres Architecture Limited | Professional & scientific | 2012 |
| Acres Construction Limited | Construction | 2021 |
| Acris Oils Limited | Wholesale & retail | 1984 |
| Acropolis Foods Ltd | Wholesale & retail | 2025 |
| Acsp Group Limited | Wholesale & retail | 2020 |
| Acti-Mind Neurodiverse CIC | Health & social care | 2026 |
| Action Alarms (Midlands) Limited | Administrative & support | 2004 |
| Action for Retrofit Limited | Professional & scientific | 2025 |
| Action Planning Consultancy Ltd | Professional & scientific | 2005 |
| Action Plumbing (Leicester) Limited | Construction | 2002 |
| Action Research & Communications Ltd | Professional & scientific | 2024 |
| Actionable Intelligence Ltd. | Information & communication | 2014 |
| Actismedia.Co.Uk Limited | Information & communication | 2014 |
| ACTIV8US Global Ltd | Professional & scientific | 2022 |
| Activate Business Solutions Ltd | Administrative & support | 2005 |
| Activated Carbon Innovation UK Ltd | Professional & scientific | 2019 |
| Active & Healthy Minds CIC | Health & social care | 2022 |
| Active AI Ltd | Information & communication | 2025 |
| Active Bilborough Community Hub CIC | Health & social care | 2024 |
| Active City Support Limited | Education | 2014 |
| Active Electrical Install Limited | Construction | 2020 |
| Active Paws Nottingham Ltd | Agriculture & fishing | 2025 |
| Active Physio Limited | Other services | 2013 |
| Active Sports Care Limited | Health & social care | 2012 |
| ACTIVE8 Building Limited | Construction | 2008 |
| Activeace Tennis Academy Ltd | Arts & recreation | 2008 |
| Activecaring Ltd | Administrative & support | 2022 |
| Activeone LLP | | 2025 |
| Activeplan Consulting Limited | Information & communication | 2009 |
| Activity Camps Nottinghamshire Ltd | Education | 2021 |
| Acton Supplies Limited | Wholesale & retail | 1996 |
| Acton Timber Yard Limited | Wholesale & retail | 2013 |
| Actor Industry Insights Midlands Ltd | Education | 2026 |
| Acts in Action CIC | Health & social care | 2024 |
| Acts Nottingham Ltd | Arts & recreation | 2023 |
| Actual Learning Ltd | Education | 2023 |
| Actualise Counselling and Therapy Ltd | Health & social care | 2026 |
| ACU Spirit Limited | Health & social care | 2018 |
| Acuity Care Group Limited | Financial services | 2020 |
| Acuity Care Holdings Limited | Financial services | 2020 |
| Acumen Asset Management Limited | Administrative & support | 2000 |
| Acumen FD Limited | Professional & scientific | 2014 |
| Acumen Ideas Factory and Project Management Limited | Information & communication | 2020 |
| Acumen Medtech Limited | Professional & scientific | 2015 |
| Acumeq Ltd | Professional & scientific | 2025 |
| Acut Above the Rest Ltd | Other services | 2019 |
| Acutebookkeeping Ltd | Professional & scientific | 2025 |
| Acworks Ltd | Construction | 2023 |
| AD and More Ltd | Information & communication | 2025 |
| AD Perry Electrical Ltd | Construction | 2021 |
| AD Redos Limited | Professional & scientific | 2019 |