| AM Digital Agency Ltd | Information & communication | 2022 |
| AM E-Tech Limited | Manufacturing | 2013 |
| AM Electrical & Training Services Limited | Construction | 2023 |
| AM HAQ Construction Ltd | Construction | 2024 |
| AM Interiors by Design Ltd | Professional & scientific | 2018 |
| AM Point Ltd | Health & social care | 2020 |
| AM Prestige Ltd | Administrative & support | 2017 |
| AM Resolutions Ltd | Professional & scientific | 2012 |
| AM Trade Service Ltd | Other services | 2025 |
| AM Venture Group Limited | Wholesale & retail | 2017 |
| AM Vision Dynamics Ltd | Wholesale & retail | 2024 |
| AM Welsh Locums Limited | Health & social care | 2020 |
| AM-ONE1 Group Ltd | Wholesale & retail | 2025 |
| AMA Group Holdings Limited | Financial services | 2025 |
| AMA Holdings Limited | Transport & logistics | 2001 |
| AMA Maintenance Ltd | Construction | 2020 |
| AMA Power Ltd | Financial services | 2025 |
| Amaans Limited | Hospitality | 2020 |
| Amadeus Property Group Limited | Construction | 2018 |
| Amafco Building Contracting Limited | Construction | 2023 |
| Amak Developments Ltd | Real estate | 2019 |
| Amaka’S Services Limited | Health & social care | 2019 |
| Amal Traders Ltd | Hospitality | 2018 |
| Amalais Ltd | Transport & logistics | 2015 |
| Amali Trading Ltd | Administrative & support | 2025 |
| Amalial Ltd | Other services | 2025 |
| Amama Sanctuary CIC | Education | 2026 |
| Aman Kumar Ventures Ltd | Wholesale & retail | 2026 |
| Amana Import Ltd | Other services | 2014 |
| Amanah Media Group Ltd. | Arts & recreation | 2025 |
| Amanah-Cymru CIC | Education | 2025 |
| Amanda Ataou Training & Coaching Limited | Other services | 2026 |
| Amanda Jewellery Limited | Wholesale & retail | 2015 |
| Amanda Townsend Ltd | Extraterritorial | 2025 |
| Amandaland Ltd | Wholesale & retail | 2003 |
| Amandeep SINGH1 Ltd | Construction | 2021 |
| Amanfhb Ltd | Wholesale & retail | 2026 |
| Amani BME Counselling CIC | Health & social care | 2023 |
| Amani Jones Ltd | Manufacturing | 2012 |
| Amanita Labs Ltd | Financial services | 2021 |
| Amanita Trading Ltd | Wholesale & retail | 2024 |
| Amanizi Group Ltd | Wholesale & retail | 2025 |
| Amann Venture Limited | Real estate | 2024 |
| Amantas PC | | 2017 |
| Amao Construction Limited | Construction | 2024 |
| Amar Hub Ltd | Wholesale & retail | 2026 |
| Amari Care Homes Ltd | Professional & scientific | 2019 |
| Amari Healthcare Ltd | Administrative & support | 2020 |
| Amari PAX Limited | Information & communication | 2022 |
| Amarillo Healthcare Ltd | Health & social care | 2016 |
| Amarjit SINGH1 Ltd | Construction | 2023 |
| Amaryllis Green Solutions Ltd | Professional & scientific | 2024 |
| Amaski Ltd | Real estate | 2013 |
| Amatin PC | | 2017 |
| Amatt Street Ltd | Wholesale & retail | 2025 |
| Amatto Group Limited | Wholesale & retail | 2023 |
| Amavi Botanica Ltd | Wholesale & retail | 2025 |
| Amayr Limited | Wholesale & retail | 2019 |
| Amayzas Ecom Retail Ltd | Wholesale & retail | 2025 |
| Amazeek Ltd | Wholesale & retail | 2025 |
| Amazing Grace Consultancy Ltd | Administrative & support | 2017 |
| Amazing Grace South Wales Limited | Hospitality | 2011 |
| Amazinstore Ltd | Wholesale & retail | 2020 |
| Amazoner Ltd | Wholesale & retail | 2024 |
| AMB Properties Cardiff Ltd | Real estate | 2023 |
| Ambassador Fire & Security Limited | Construction | 2009 |
| Ambassador Management Systems Ltd | Information & communication | 2017 |
| Ambassador Transfers Ltd | Transport & logistics | 2024 |
| Ambaya Company for Wholesale and Retail Trade Ltd | Wholesale & retail | 2025 |
| Ambela Limited | Wholesale & retail | 2024 |
| Amber Enterprises Group Ltd | Professional & scientific | 2016 |
| Amber Fragrances Ltd | Wholesale & retail | 2018 |
| Amber Harbour Properties Ltd | Real estate | 2021 |
| Amber Iron Systems Ltd | Information & communication | 2025 |
| Amber Lake Holdings Limited | Financial services | 2024 |
| Amber Lake Investments Limited | Real estate | 2024 |
| Amber Monkey Ltd | Education | 2019 |
| Amber Project Management Limited | Construction | 2025 |
| Amber Property ( South West ) Limited | Real estate | 2010 |
| Amber Pubs Limited | Hospitality | 2017 |
| Amberblend Limited | Real estate | 2007 |
| Ambercloud Limited | Health & social care | 2006 |
| Ambercosy Ltd | Wholesale & retail | 2020 |
| Amberley Motors Ltd | Wholesale & retail | 2018 |
| Amberline Care Ltd | Health & social care | 2016 |
| Amberoak Limited | Health & social care | 2010 |
| Ambers Club Ltd | Hospitality | 2024 |
| Ambervale Limited | Transport & logistics | 2017 |
| Ambicio Partners LLP | | 2025 |
| Ambient Air Control Limited | Construction | 1998 |
| Ambientair Ltd | Wholesale & retail | 2009 |
| Ambikaa Ltd | Hospitality | 2020 |
| Ambos AI Limited | Information & communication | 2025 |
| Ambra Arli Properties Ltd | Real estate | 2026 |
| Ambramo Solutions Ltd | Wholesale & retail | 2021 |
| Ambrose and Connor Services Limited | Other services | 2018 |
| Ambrose Electrical Limited | Manufacturing | 2013 |
| Ambrosia Pharma Ltd | Health & social care | 2018 |
| Ambs Barbers Ltd | Other services | 2025 |
| Ambserve Ltd | Arts & recreation | 2007 |