| AI Digital Training Limited | Professional & scientific | 2019 |
| AI Marketing LAB Ltd | Professional & scientific | 2024 |
| AI3 Partners Ltd | Information & communication | 2012 |
| Aiauraconsulting Ltd | Information & communication | 2026 |
| AIC Marketing Ltd | Professional & scientific | 2025 |
| Aidani Ltd | Wholesale & retail | 2024 |
| Aidanic Bioprime Limited | Wholesale & retail | 2026 |
| AIE Software Limited | Information & communication | 2017 |
| AIM Recovery Limited | Transport & logistics | 2023 |
| Aimarch Holdings Ltd | Professional & scientific | 2024 |
| AIP Properties Ltd | Real estate | 2018 |
| AIP Software Ltd | Information & communication | 2020 |
| Air Climate Conditioning Limited | Construction | 2018 |
| Airande Global Distribution (UK) Limited | Wholesale & retail | 2024 |
| Airfare Lincoln Ltd | Transport & logistics | 2026 |
| Airlesspro Ltd | Wholesale & retail | 2011 |
| Airsoft Armourer Ltd | Arts & recreation | 2022 |
| Aistrup Hind Organ Builders Ltd | Manufacturing | 2003 |
| AJ & FE Priestley (Holdings) Limited | Financial services | 2025 |
| AJ & FE Priestley Ltd | Real estate | 2022 |
| AJ & JK Collectibles Ltd | Wholesale & retail | 2025 |
| AJ Cars & Commercials Ltd | Wholesale & retail | 2023 |
| AJ H Transport Ltd | Transport & logistics | 2024 |
| AJ Machin Construction Ltd | Construction | 2019 |
| AJB Consultancy Ltd | Professional & scientific | 2026 |
| AJB Investments Limited | Real estate | 2019 |
| Ajct Limited | Construction | 2015 |
| AJD Strategic Finance Limited | Professional & scientific | 2017 |
| Ajet Drain Services Limited | Administrative & support | 2004 |
| AJI Solutions Limited | Professional & scientific | 2017 |
| AJM Business Services Limited | Administrative & support | 2009 |
| Ajob Business Finance Limited | Financial services | 2021 |
| AJP Developments Limited | Real estate | 2019 |
| AJR Taylor Farms Limited | Agriculture & fishing | 2003 |
| AJS Construction Consult Limited | Construction | 2023 |
| Ajss Limited | Health & social care | 2012 |
| AJT Web Solutions Ltd | Information & communication | 2026 |
| AK Builders Lincoln Limited | Administrative & support | 2023 |
| AK Hot TUB Holiday Homes Ltd | Real estate | 2018 |
| AK Navenby Ltd | Hospitality | 2023 |
| AKB Limited | Transport & logistics | 2016 |
| Akdag Pizza Ltd | Hospitality | 2022 |
| Akedo Gaming Ltd | Arts & recreation | 2018 |
| Akersten Ltd | Professional & scientific | 2020 |
| AKH Property Maintenance Ltd | Construction | 2022 |
| Akhem Care Training Limited | Administrative & support | 2025 |
| AKO Groundworks Limited | Construction | 2020 |
| AL NUR Limited | Hospitality | 2024 |
| AL TAJ Supermarket Ltd | Wholesale & retail | 2025 |
| Al&Bo Ltd | Transport & logistics | 2024 |
| Al-Darr Ltd | Real estate | 2024 |
| Alam & Fatima Ltd | Health & social care | 2014 |
| Alan Hunt Transport Solutions Ltd | Transport & logistics | 2023 |
| Alan Parkin Engineering Ltd | Professional & scientific | 2018 |
| Alannalherbert Ltd | Arts & recreation | 2026 |
| Alaris Investment Holdings UK Limited | Manufacturing | 2016 |
| Alaris the RF Technology Group Ltd | Financial services | 2025 |
| Alastair Marsh Ltd | Health & social care | 2011 |
| Alaya Trades Ltd | Hospitality | 2025 |
| Alberellis Flooring Limited | Construction | 2022 |
| Albon Abbey Ltd | Hospitality | 2021 |
| Alchemy Agronomy Ltd | Agriculture & fishing | 2023 |
| Alcraft Motor Company Ltd | Manufacturing | 2014 |
| Alder Housing Ltd | Real estate | 2022 |
| Aldridge Autos Limited | Wholesale & retail | 2019 |
| Alef-Null Design Limited | Information & communication | 1994 |
| Aleksandrs Antonenko Properties Ltd | Real estate | 2026 |
| Alekscleaning Limited | Manufacturing | 2020 |
| Alex Albone Limited | Real estate | 2019 |
| Alex Eagle Store Limited | Wholesale & retail | 2013 |
| Alex Garner Ltd | Wholesale & retail | 2026 |
| Alex Ross Ltd | Professional & scientific | 2025 |
| Alexander Akrill Limited | Administrative & support | 2004 |
| Alexander Akrill Services Limited | Construction | 2017 |
| Alexander Realty Limited | Real estate | 2024 |
| Alexandra Management Services Limited | Households | 2001 |
| Alexicco Digital Marketing Ltd | Information & communication | 2024 |
| Alfa Properties (Keyingham) Ltd | Real estate | 2003 |
| Alfred Street Lincoln Management Company Limited | Real estate | 2023 |
| Alfstrat Ltd | Transport & logistics | 2025 |
| ALI Afzal Sanghra Ltd | Wholesale & retail | 2025 |
| ALI Soft Works Ltd | Information & communication | 2026 |
| ALI Store Ltd | Wholesale & retail | 2025 |
| Alice Ackroyd Consulting Limited | Professional & scientific | 2018 |
| Alice Strange Flowers Limited | Wholesale & retail | 2015 |
| Alika Selfcare Ltd | Other services | 2022 |
| Alimac Consultants Ltd | Information & communication | 2025 |
| Alison Hurton Ltd | Professional & scientific | 2011 |
| Alive Church Lincoln | Other services | 2011 |
| Alive Enterprises Limited | Administrative & support | 2006 |
| Alix Day Ltd | Professional & scientific | 2020 |
| Alix London Ltd | Wholesale & retail | 2022 |
| ALL in Construction Ltd | Construction | 2018 |
| ALL Lettings Limited | Real estate | 2021 |
| ALL Occasions Casino Limited | Arts & recreation | 2014 |
| ALL Round Automotive Limited | Wholesale & retail | 2021 |
| ALL4WOMAN Hygiene Limited | Other services | 2009 |
| Allders (UK) PLC | Extraterritorial | 2012 |
| Allem Transport Ltd | Transport & logistics | 2024 |
| Allen and Rees Holdings Ltd | Financial services | 2026 |