| 11 Stars Mobile Ltd | Wholesale & retail | 2024 |
| 13TH Apostle Ltd | Information & communication | 2014 |
| 14TWENTY Productions Ltd | Administrative & support | 2025 |
| 15A Newry Street Limited | Households | 2009 |
| A C Tek-Sol Ltd | Wholesale & retail | 2017 |
| A T Jones Building & Damp Proofing Ltd | Construction | 2016 |
| A&U Solutions Ltd | Wholesale & retail | 2024 |
| AA Serviced Stays Ltd | Real estate | 2025 |
| AAA Holyhead Taxi Limited | Transport & logistics | 2026 |
| AARON2K Ltd | Professional & scientific | 2012 |
| Abacus Marine Limited | Other services | 2025 |
| Academi Natur MÔN Ltd | Education | 2024 |
| Adeiladwyr MON CYF | Construction | 2015 |
| Adrian Couriers Ltd | Transport & logistics | 2025 |
| Advanced Modern Methods of Construction Limited | Construction | 2022 |
| AE & at Lewis (Construction) Ltd | Construction | 2026 |
| AE & at Lewis (Groundcare) Ltd | Construction | 2026 |
| AE & at Lewis (Waste) Ltd | Water & waste | 2026 |
| AE & at Lewis Limited | Construction | 2004 |
| Aerotek Services UK Limited | Manufacturing | 2023 |
| Agra Restaurant & Takeaway Ltd | Hospitality | 2025 |
| Agrimon Ltd | Agriculture & fishing | 2011 |
| AJ Property Investors Ltd | Real estate | 2024 |
| AK Rental Properties Limited | Real estate | 2023 |
| Alfie CBI Limited | Hospitality | 2013 |
| Alwyn Jones Transport (NW) Ltd | Transport & logistics | 2026 |
| Alwyn Jones Transport Limited | Transport & logistics | 2020 |
| Amalavida Property Ltd | Real estate | 2023 |
| Angel Delicacy Limited | Hospitality | 2025 |
| Anglesey Academy Limited | Hospitality | 2012 |
| Anglesey Auto Body Ltd | Wholesale & retail | 2020 |
| Anglesey Autofest CIC | Administrative & support | 2023 |
| Anglesey Builders Limited | Construction | 2014 |
| Anglesey Charcuterie Ltd | Manufacturing | 2023 |
| Anglesey Click to Book Ltd | Real estate | 2025 |
| Anglesey Executive Travel Limited | Transport & logistics | 2021 |
| Anglesey Farrier Services Ltd | Other services | 2018 |
| Anglesey Foods Ltd | Manufacturing | 2023 |
| Anglesey Gardening Ltd | Administrative & support | 2018 |
| Anglesey Holidays Limited | Administrative & support | 2014 |
| Anglesey Honey Limited | Agriculture & fishing | 2026 |
| Anglesey Island Holidays Limited | Hospitality | 2025 |
| Anglesey Mould & Press Limited | Manufacturing | 2002 |
| Anglesey Padel Ltd | Arts & recreation | 2025 |
| Anglesey Pet Clinic Limited | Professional & scientific | 2006 |
| Anglesey Potato Company Limited | Agriculture & fishing | 2019 |
| Anglesey Retail Training Solutions Limited | Education | 2013 |
| Anglesey Sea Food Ltd | Agriculture & fishing | 2020 |
| Anglesey Shooting and Fishing Limited | Arts & recreation | 1978 |
| Anglesey Smiles Limited | Health & social care | 2024 |
| Anglesey Soap Ltd | Wholesale & retail | 2019 |
| Anglesey Spirit Company Limited | Manufacturing | 2019 |
| Anglesey Wellbeing Limited | Health & social care | 2024 |
| ARA Flooring Solutions Ltd | Wholesale & retail | 2023 |
| Archdruid Interactive Ltd | Information & communication | 2024 |
| Argraig Consulting Ltd | Professional & scientific | 2023 |
| Arish Barber Ltd | Other services | 2025 |
| Arjuun Trading Ltd | Wholesale & retail | 2018 |
| ARW Engineering Ltd | Professional & scientific | 2022 |
| Ashvin Trading Ltd | Wholesale & retail | 2018 |
| Ashwrk Ltd | Information & communication | 2026 |
| Asset Safeguard (UK) Ltd | Other services | 2025 |
| Atom Health & Safety Ltd | Professional & scientific | 2018 |
| Atomark Energy Ltd | Professional & scientific | 2019 |
| Audio Books Limited | Information & communication | 2021 |
| AVA Atrium Ltd | Hospitality | 2026 |
| AVA Automations Ltd | Information & communication | 2025 |
| Awel MOR CYF | Information & communication | 2018 |
| Awel-Y-Môr Holdings Limited | Real estate | 2021 |
| AWH Plant Limited | Construction | 2024 |
| AX Digital Ltd | Information & communication | 2025 |
| AX Fitness Ltd | Wholesale & retail | 2018 |
| AX Pods Ltd | Wholesale & retail | 2026 |
| AX Property Ltd | Real estate | 2019 |
| B&A Education Limited | Professional & scientific | 2011 |
| B.C. Services (Anglesey) Limited | Construction | 2004 |
| Bago Properties Limited | Administrative & support | 1998 |
| Bangor Digz Ltd | Real estate | 2023 |
| BB Auto's (Anglesey) Ltd | Wholesale & retail | 2025 |
| Blakes On-Site Services Limited | Manufacturing | 2012 |
| BLB Contractors (Anglesey) Limited | Construction | 2025 |
| Blobme Limited | Information & communication | 2026 |
| Blue Sky Technologies Limited | Information & communication | 1999 |
| Bobs's Property Maintenance Ltd | Construction | 2023 |
| Bodowen Kennels Ltd | Agriculture & fishing | 2025 |
| Boncyn Limited | Hospitality | 2025 |
| Boobaroo Limited | Health & social care | 2025 |
| Books and Brews Ltd | Wholesale & retail | 2025 |
| Bootcampdrivers.Com Ltd | Information & communication | 2019 |
| Boucher Engineering Ltd | Professional & scientific | 2023 |
| Bounce Rentals Ltd | Real estate | 2019 |
| Braddan Limited | Information & communication | 2024 |
| Bragdy Cybi Ltd | Manufacturing | 2019 |
| Bridge Stone Company (GBS) Limited | Real estate | 2018 |
| BRO MÔN | Other services | 2020 |
| Bryn Goleu (SB) Limited | Real estate | 2013 |
| Bryn MÔR Drone Solutions Limited | Information & communication | 2022 |
| Bryngwran Cymunedol Ltd. | Hospitality | 2015 |
| Bulmer Leisure Limited | Financial services | 2020 |
| BY Phyra Creative Studio Ltd | Information & communication | 2025 |