| 01438837 Limited | Professional & scientific | 1979 |
| 03804007 Limited | Professional & scientific | 1999 |
| 10 Adamson Road Limited | Professional & scientific | 1972 |
| 11 Burrows Road Limited | Households | 2007 |
| 141 Oxford Street Management Company Limited | Real estate | 2013 |
| 1510 Consulting Limited | Wholesale & retail | 2021 |
| 1922 Law Limited | Administrative & support | 2020 |
| 1ST Choice Hauliers Ltd | Transport & logistics | 2017 |
| 1ST Class Building Contractors Ltd | Construction | 2018 |
| 21ST Century Vehicles Limited | Wholesale & retail | 2009 |
| 230 (Wales) Electrical and Solar Contractors Ltd | Extraterritorial | 2015 |
| 280GRAMMI Ltd | Hospitality | 2024 |
| 360AD Limited | Professional & scientific | 2017 |
| 369 Property Group Ltd | Real estate | 2025 |
| 3DE Property Ltd | Real estate | 2023 |
| 4 Construction Group Ltd | Education | 2025 |
| 4182 Consulting Limited | Professional & scientific | 2025 |
| 47 Park ST Limited | Real estate | 2019 |
| 49 ST Johns Villas RTM Company Limited | Real estate | 2005 |
| 4EVAYOUNG Limited | Other services | 2012 |
| 4EVER Smiles Ltd | Health & social care | 2024 |
| 5 Blackall Road Management Company Limited | Households | 1990 |
| 5 Star Properties (SW) Ltd | Construction | 2021 |
| 5 Star Weddings Ltd | Professional & scientific | 2018 |
| 51 Latitude Management Company Limited | Households | 2016 |
| 51 Stanley Road Limited | Real estate | 2023 |
| 55 Plus Waterside LLP | | 2012 |
| 5ADR Limited | Households | 2016 |
| 7&11 Ltd | Wholesale & retail | 2024 |
| A & K Blackmill Ltd | Wholesale & retail | 2020 |
| A & M Group Properties Limited | Households | 2024 |
| A & M Group Services Limited | Wholesale & retail | 2023 |
| A & M Group Storage Limited | Transport & logistics | 2023 |
| A & M Group UK Holdings Limited | Wholesale & retail | 2023 |
| A and J Energy Advisors Ltd | Other services | 2024 |
| A Classic Barbers Ltd | Other services | 2020 |
| A Head of the Game Nutrition Limited | Hospitality | 2020 |
| A J E Estates Limited | Real estate | 2014 |
| A J Mechanical & Electrical Services Limited | Construction | 2002 |
| A J Plumbing Services Limited | Construction | 2012 |
| A Keedwell Holdings Limited | Transport & logistics | 2017 |
| A Killer Next Door Ltd | Information & communication | 2019 |
| A N H (Bridgend) Ltd | Other services | 2018 |
| A One Construction Bridgend Limited | Construction | 2012 |
| A S Construction & Design Ltd | Construction | 2011 |
| A&A Zajac Property Ltd | Real estate | 2025 |
| A&N Mobile Ltd | Other services | 2021 |
| A&P Fire Solutions Ltd | Financial services | 2026 |
| A&R Contract Cleaning Specialist Ltd | Administrative & support | 2013 |
| A. N. Supplies (Wholesale Electrical Distributors) Limited | Wholesale & retail | 1976 |
| A. T. Property Lettings Limited | Real estate | 2021 |
| A.C. Contract Interiors Limited | Manufacturing | 2011 |
| A.C.E Carpentry & Construction Ltd | Manufacturing | 2019 |
| A.G.Industrial Limited | Real estate | 2002 |
| A.J. Evans (Holdings) Limited | Wholesale & retail | 2024 |
| A.J. Evans Limited | Wholesale & retail | 1999 |
| A.M.J. Courier Services Limited | Transport & logistics | 2021 |
| A.P.H Products Ltd | Wholesale & retail | 2023 |
| A.T. Dental Laboratory Ltd | Health & social care | 2020 |
| A1 Building & Construction (Wales) Limited | Construction | 2010 |
| A1 Electronic Designs Ltd | Manufacturing | 2012 |
| A2E Energy Assessors Ltd | Professional & scientific | 2019 |
| Aaronie Mary Ltd | Health & social care | 2016 |
| AAW Building Contractors (Bridgend) Ltd | Construction | 2026 |
| AB Removals UK Ltd | Water & waste | 2024 |
| AB Services Ltd | Water & waste | 2021 |
| Abaf Homes Limited | Real estate | 2025 |
| Abbey Gardens (Ewenny) Management Company Limited | Households | 2017 |
| Abbeymile Properties Limited | Real estate | 2002 |
| Aberavon Properties LLP | | 2004 |
| Ability Assist Ltd | Wholesale & retail | 2024 |
| Abira Retail Ltd | Wholesale & retail | 2019 |
| Ablehart Limited | Extraterritorial | 2026 |
| Ableplan Limited | Extraterritorial | 2026 |
| Absolute Dental Cardiff Limited | Health & social care | 2024 |
| Absolute Dental Centre Limited | Health & social care | 2008 |
| Absolute Health Group Limited | Health & social care | 2022 |
| Absolute Lifting Gear/Ndt Services Ltd | Professional & scientific | 2017 |
| Absorb-Tech Limited | Professional & scientific | 2025 |
| AC2 Business Solutions Ltd | Wholesale & retail | 2026 |
| ACB Surveys Ltd | Construction | 2019 |
| Acceleosoft Limited | Information & communication | 2019 |
| Access Consulting Services Ltd | Information & communication | 2017 |
| Access Scaffold Ltd | Other services | 2016 |
| Accessfirst Initiative Limited | Administrative & support | 2024 |
| Accresco Limited | Information & communication | 2025 |
| ACD Skips Limited | Water & waste | 1997 |
| Acdf Health Limited | Extraterritorial | 2023 |
| Ace Life Centres Limited | Health & social care | 2017 |
| Acecroft Limited | Extraterritorial | 2024 |
| Acemaster Services Limited | Wholesale & retail | 1999 |
| Acerise LLP | | 2022 |
| Acethorn Limited | Professional & scientific | 2025 |
| ACH Llynfi Ltd | Health & social care | 2026 |
| ACJ Property Management Ltd | Real estate | 2026 |
| Acquest Homes Ltd | Real estate | 2025 |
| Acrefray Limited | Extraterritorial | 2025 |
| Acrehale Limited | Extraterritorial | 2026 |
| Acsrk Ltd | Health & social care | 2019 |
| Action Doors Ltd | Administrative & support | 2017 |