| Ab&Mrv Ltd | Administrative & support | 2026 |
| ABA Property Holdings Ltd | Financial services | 2024 |
| Abbas ALI Limited | Wholesale & retail | 2023 |
| Abbey Analytics Ltd | Information & communication | 2022 |
| Abbey Bathrooms Ltd | Wholesale & retail | 2025 |
| Abbey Lane Estate Planning Limited | Professional & scientific | 2018 |
| Abbey Trade Hub Limited | Wholesale & retail | 2026 |
| Abbey Village Limited | Health & social care | 2009 |
| Abbinaccessories Limited | Wholesale & retail | 2017 |
| Abbo GAS Services Limited | Construction | 2018 |
| Abby's Travel Ltd | Transport & logistics | 2026 |
| Abbys Curry House Ltd | Wholesale & retail | 2023 |
| ABC Car Parts Ltd | Wholesale & retail | 2024 |
| ABC Creative House Limited | Professional & scientific | 2026 |
| ABD Tech Limited | Wholesale & retail | 2024 |
| Abdali Foods Ltd | Wholesale & retail | 2021 |
| Abdul REH Ltd | Wholesale & retail | 2025 |
| ABE Engineering Limited | Manufacturing | 2021 |
| Abele Health Ltd | Health & social care | 2025 |
| ABF Projects Ltd | Professional & scientific | 2014 |
| Abfit Web Solutions Ltd | Information & communication | 2023 |
| Abifields Ltd | Administrative & support | 2024 |
| Ability Lift Truck Training Ltd | Education | 2024 |
| ABL Comms Ltd | Information & communication | 2020 |
| Abode Financial Ltd | Financial services | 2023 |
| Abode Lettings and Property Management LLP | | 2007 |
| Abode Mortgage Services Limited | Financial services | 2023 |
| Abode Property Holdings and Management Ltd | Real estate | 2021 |
| Abodeable Ltd | Real estate | 2024 |
| Abraham Delights Ltd | Wholesale & retail | 2025 |
| Abrahams Brickwork Ltd | Manufacturing | 2019 |
| Abrahone Engineering Limited | Manufacturing | 2003 |
| ABS Lettings Limited | Real estate | 2018 |
| ABS Securities Holdings Ltd | Construction | 2018 |
| ABS Securities Ltd | Administrative & support | 2016 |
| Absolute Bodyworx Limited | Wholesale & retail | 2024 |
| Absolute Sandwich Solutions Ltd | Hospitality | 2015 |
| Absolute Vision Engineering Ltd | Information & communication | 2023 |
| Abyss Subsea Ltd | Professional & scientific | 2026 |
| AC Aggregates Group Ltd | Financial services | 2022 |
| AC Aggregates Ltd | Transport & logistics | 2008 |
| AC Building Products Ltd | Construction | 2022 |
| AC Cement Ltd | Wholesale & retail | 2020 |
| AC Commodities Ltd | Water & waste | 2013 |
| AC Family Protection Ltd | Financial services | 2026 |
| AC Fleet Solutions Ltd | Transport & logistics | 2017 |
| AC Group Logistics Ltd | Transport & logistics | 2023 |
| AC Port Services Ltd | Financial services | 2026 |
| AC Property Developments (Yorkshire) Ltd | Construction | 2018 |
| AC Recycling Ltd | Transport & logistics | 2017 |
| Acacia Training and Development Ltd | Education | 2002 |
| Academix Learning Foundation CIC | Education | 2024 |
| Academix Learning Limited | Education | 2024 |
| ACB Builder Limited | Construction | 2023 |
| ACB Holdings Ltd | Professional & scientific | 2024 |
| Access 4 Finance Limited | Financial services | 2010 |
| Access GAS Limited | Mining & quarrying | 2020 |
| Access Money (Group) Limited | Financial services | 2020 |
| Accirro Ltd | Administrative & support | 2022 |
| Accountancy Payroll & Taxation Limited | Professional & scientific | 2012 |
| Accounza Ltd | Professional & scientific | 2025 |
| Acdev Limited | Real estate | 1967 |
| Ace Auto Group Ltd | Wholesale & retail | 2025 |
| Ace Balloons Limited | Arts & recreation | 2025 |
| Ace Crazy Golf Hire Limited | Arts & recreation | 2023 |
| Ace Drains (Yorkshire) Limited | Other services | 2022 |
| Ace Electrical Installation Contractors Ltd | Construction | 2025 |
| Ace Engineering Group Ltd | Professional & scientific | 2025 |
| Ace Engineers Ltd | Professional & scientific | 2023 |
| Ace Partitions & Ceilings (Holdings) Limited | Financial services | 2017 |
| Ace Partitions and Ceilings Limited | Construction | 1997 |
| Ace Party Limited | Arts & recreation | 2021 |
| Ace Properties & Letting Ltd | Real estate | 2024 |
| Ace Social Care Ltd | Health & social care | 2015 |
| Ace Stores Management Limited | Transport & logistics | 2025 |
| Acentus Commercial Ltd | Real estate | 2025 |
| ACG Mechanical Site Fitters Limited | Construction | 2017 |
| ACH Administration Ltd | Professional & scientific | 2024 |
| Achieve Your Goals CIC | Education | 2021 |
| Achillies Limited | Hospitality | 2023 |
| ACL Interiors Ltd | Construction | 2009 |
| ACM Bearings Limited | Manufacturing | 1991 |
| Acmetrack Limited | Extraterritorial | 1972 |
| Acorn Damp Proofing Ltd | Construction | 2017 |
| Acorn Industrial Services Group Ltd | Wholesale & retail | 2005 |
| Acorn Industrial Services Limited | Wholesale & retail | 1983 |
| Acorn Skips Limited | Water & waste | 2020 |
| ACP HRS Limited | Professional & scientific | 2021 |
| ACP Pharmacy Group Ltd | Financial services | 2026 |
| ACP Property Group Ltd | Financial services | 2026 |
| Acquiprop Limited | Real estate | 2017 |
| Acres Hill Holdings (SY) Ltd | Financial services | 2026 |
| Across Solutions Ltd | Construction | 2022 |
| Acsupplysuk Ltd | Wholesale & retail | 2025 |
| ACT Couriers and Transport Limited | Transport & logistics | 2022 |
| Action Housing and Support Limited | Other services | 1981 |
| Activate Rawmarsh | Health & social care | 2012 |
| Active Care Plus Ltd | Other services | 2016 |
| Active Demolition and Waste Services Ltd | Water & waste | 2016 |
| Active for Life Solutions Limited | Health & social care | 2015 |