| Advanced Composite Manufacturing Limited | Extraterritorial | 2008 |
| Adventures in Wood Limited | Construction | 2020 |
| Aegean Breeze Ltd | Administrative & support | 2023 |
| Aesthetics Plus - Health and Wellbeing Ltd | Other services | 2024 |
| AFK Trasport Ltd | Transport & logistics | 2025 |
| Afrotec Hair & Beauty Limited | Other services | 2011 |
| Agape Transport Ltd | Transport & logistics | 2019 |
| Agdas Limited | Wholesale & retail | 2025 |
| Agemet Limited | Professional & scientific | 1977 |
| Agile Business Support Services Limited | Administrative & support | 2020 |
| Agricare Lincolnshire Limited | Agriculture & fishing | 2017 |
| Agricultural Machinery Sales Limited | Extraterritorial | 2010 |
| Agricultural Tyres & Wheels (UK) Ltd | Wholesale & retail | 2025 |
| Agricultural Tyres & Wheels Limited | Wholesale & retail | 2009 |
| Agritrition Ltd | Agriculture & fishing | 2011 |
| Agromark Fresh Produce UK Limited | Wholesale & retail | 2019 |
| AGS Trans Ltd | Transport & logistics | 2017 |
| Ahmed EYE Care Services Limited | Health & social care | 2011 |
| Aibb Marketing Ltd | Other services | 2026 |
| Aida & S Car Parts Ltd | Wholesale & retail | 2024 |
| Aidexo Ltd | Information & communication | 2020 |
| AIJ Road Transport Ltd | Transport & logistics | 2018 |
| Aimex Solutions Ltd | Transport & logistics | 2022 |
| Air-Switch Limited | Manufacturing | 2021 |
| Aireja Limited | Transport & logistics | 2017 |
| AIS Property Boston Limited | Real estate | 2011 |
| Aisha Z Y Commercials Ltd | Real estate | 2022 |
| Aisha Z Y Ltd | Real estate | 2021 |
| Aj's Auto Repairs Ltd | Wholesale & retail | 2023 |
| Aj's Taxi Ltd | Transport & logistics | 2026 |
| AJH Refrigeration Ltd | Administrative & support | 2015 |
| AJM and EFE Limited | Hospitality | 2025 |
| AJM I (Lincs) Unlimited | Professional & scientific | 2013 |
| AJM P (Lincs) Ltd | Real estate | 2013 |
| AJN Food Limited | Hospitality | 2019 |
| AJS Interactive Ltd | Hospitality | 2024 |
| AJT Estimating Ltd | Wholesale & retail | 2019 |
| AK Quality Fruit and VEG Ltd | Wholesale & retail | 2026 |
| AK Sales Ltd | Wholesale & retail | 2019 |
| AKA Distributions Ltd | Wholesale & retail | 2026 |
| Akcustoms Ltd | Administrative & support | 2021 |
| AL Alliance Ltd | Other services | 2017 |
| AL Jannat Ltd | Wholesale & retail | 2021 |
| AL Rahman Properties Ltd | Real estate | 2012 |
| AL Removals Ltd | Transport & logistics | 2024 |
| Al-Wahhaab Medics Ltd | Health & social care | 2012 |
| Alan Louth Plumbing and Heating Services Ltd | Construction | 2025 |
| Alarmline Security Ltd | Administrative & support | 2012 |
| Alcazar Brewing Company Limited | Manufacturing | 2001 |
| Alchemy Farms Ltd. | Agriculture & fishing | 2002 |
| Alcyon Property Limited | Real estate | 2015 |
| Alder Grove Management Company Limited | Households | 1997 |
| Alec Coney (Farms) Limited | Agriculture & fishing | 1962 |
| Aleh Trans Ltd | Transport & logistics | 2026 |
| Aleksoll Ltd | Transport & logistics | 2026 |
| Aleksotas Ltd | Construction | 2023 |
| Alex Amberway Limited | Transport & logistics | 2015 |
| Alexander Keenan Notarial Services Limited | Professional & scientific | 2016 |
| Alexandra SRL Ltd | Wholesale & retail | 2026 |
| Alexandru (Lincs) Ltd | Transport & logistics | 2021 |
| Alistair Mitchell Co. Limited | Professional & scientific | 2004 |
| ALL About Publishing Ltd | Information & communication | 2015 |
| ALL Agro Services Limited | Wholesale & retail | 2023 |
| ALL Together Removals Ltd | Transport & logistics | 2023 |
| Alliance Transport UK Ltd | Transport & logistics | 2021 |
| Allington Lettings Ltd | Real estate | 2024 |
| Allium Crop Solutions Limited | Wholesale & retail | 2002 |
| ALP Financial Solutions Ltd | Financial services | 2024 |
| Alphacroft Limited | Other services | 2022 |
| Alrita Ltd | Real estate | 2022 |
| Althera Ltd | Professional & scientific | 2022 |
| ALU Transport Logistics Limited | Manufacturing | 2020 |
| Amaroni 3PL Services Limited | Transport & logistics | 2019 |
| Amaroni Limited | Financial services | 2019 |
| Amateur World Football Association | Education | 2023 |
| Amateur World Football CUP Limited | Education | 2025 |
| Amaya Indian and Bangladeshi Takeaway Limited | Hospitality | 2025 |
| Amber Food Retail Limited | Wholesale & retail | 2021 |
| Amber Truck Ltd | Transport & logistics | 2024 |
| Ambersea Limited | Wholesale & retail | 2011 |
| Ambrose Lighton,Limited | Agriculture & fishing | 1925 |
| American Caravans Ltd | Wholesale & retail | 2023 |
| American Tower UK Corp. | | 2012 |
| AMG Medical Ltd | Health & social care | 2023 |
| Amirus Limited | Wholesale & retail | 2025 |
| Amnis Limited | Administrative & support | 2005 |
| Amperland Ltd | Construction | 2026 |
| Analyser Consulting Limited | Professional & scientific | 2020 |
| ANC Drainage and Jetting Solutions Ltd | Administrative & support | 2023 |
| Andrei Trans Limited | Administrative & support | 2020 |
| Andrejusn Limited | Transport & logistics | 2020 |
| Andrew Firth Limited | Administrative & support | 2022 |
| Andrew's Angels Childcare Ltd. | Health & social care | 2018 |
| Andreww Ltd | Transport & logistics | 2019 |
| Andromex Logistics Ltd | Wholesale & retail | 2022 |
| Andy Cridland Trailer Services Ltd | Wholesale & retail | 2022 |
| Aniacom UK Ltd | Transport & logistics | 2024 |
| Animal Alliance | Agriculture & fishing | 2023 |
| Animal Alliance Rescue and Rehoming CIC | Other services | 2024 |
| ANK Holding Ltd | Real estate | 2026 |