| Alkat Property Limited | Real estate | 2022 |
| ALL About Sport Limited | Professional & scientific | 2019 |
| ALL Aspects Roofing York Limited | Construction | 2022 |
| ALL Aspects Travel Limited | Administrative & support | 2023 |
| ALL Design & Print Limited | Manufacturing | 2010 |
| ALL in Control Ltd | Information & communication | 2020 |
| ALL in the Detail Plasterers Limited | Construction | 2023 |
| ALL Joinery Services Limited | Construction | 1998 |
| ALL OUT Cricket Coaching Limited | Arts & recreation | 2014 |
| ALL Points North Ltd | Real estate | 2020 |
| ALL Round Developments Limited | Construction | 2018 |
| ALL Seasons Farming Ltd | Agriculture & fishing | 2020 |
| ALL Star Football Academy Franchises Ltd | Education | 2016 |
| ALL Star Football Academy Ltd | Education | 2014 |
| ALL Star Football Group Limited | Education | 2015 |
| ALL Things Birth & Beyond Limited | Other services | 2017 |
| ALL Things Franchise Ltd | Administrative & support | 2018 |
| ALL Trades Construction Limited | Construction | 2025 |
| ALL Travel (York) Limited | Professional & scientific | 2013 |
| ALL Vehicles Great and Small Ltd | Administrative & support | 2025 |
| All's Well Entertainment Limited | Extraterritorial | 2016 |
| All-Out Dents Limited | Wholesale & retail | 2006 |
| All-Star Pups Ltd | Other services | 2022 |
| ALL1NETWORK Ltd | Professional & scientific | 2020 |
| Alla’S House Ltd | Wholesale & retail | 2022 |
| Allen Legal Services Limited | Professional & scientific | 2024 |
| Allenby Cronshaw Electrical Ltd | Construction | 2015 |
| Allenby Design Ltd | Professional & scientific | 2020 |
| Allenchrome Electroplating Limited | Manufacturing | 1984 |
| Allensway Recycling (Grimsby) Limited | Water & waste | 2009 |
| Allensway Recycling Limited | Water & waste | 2003 |
| Allensway Transport Limited | Transport & logistics | 2004 |
| Allergen Checker 2020 Ltd | Hospitality | 2020 |
| Allerthorpe Construction Limited | Agriculture & fishing | 1987 |
| Allerthorpe Golf and Country Park Limited | Hospitality | 2019 |
| Allie BEE Ltd | Other services | 2023 |
| Allied Commerce Limited | Extraterritorial | 2009 |
| Allinscience Ltd | Professional & scientific | 2010 |
| Allinson Hoarding Installation Services Limited | Construction | 2023 |
| Allison Minster Properties Limited | Real estate | 1998 |
| Allison PHX Ltd | Real estate | 2025 |
| Allium CHP Limited | Energy | 2021 |
| Allium Helmsley Group Ltd | Financial services | 2024 |
| Allium Helmsley Ltd | Energy | 2015 |
| Allman Solutions Ltd | Information & communication | 2026 |
| Allot Healthcare Services Ltd | Health & social care | 2014 |
| Allsports Event Management Ltd | Professional & scientific | 2009 |
| Allsports Service Ltd | Arts & recreation | 2018 |
| Allt Y Celyn (Rhos) Management Company Limited | Households | 2016 |
| Allure Interiors Ltd | Professional & scientific | 2022 |
| Alma Anderson Limited | Administrative & support | 2016 |
| Alma Pelly Limited | Professional & scientific | 2016 |
| Alma Terrace Management Company Limited | Households | 2004 |
| Almaz York Limited | Hospitality | 2018 |
| Almira Barbers Ltd | Other services | 2021 |
| Alms Consultants Ltd | Professional & scientific | 2024 |
| Alne Consulting Ltd | Professional & scientific | 2023 |
| Alne Fitness Limited | Arts & recreation | 2024 |
| Alne Holiday Cottages Ltd | Hospitality | 2020 |
| Alne Pre-School Playgroup | Education | 2012 |
| Alness Ltd | Professional & scientific | 2015 |
| Alnwick Property Limited | Real estate | 2024 |
| ALP Architecture Ltd | Professional & scientific | 2021 |
| Alpha Bravo Creative Drinks Limited | Information & communication | 2026 |
| Alpha Cars York Ltd | Transport & logistics | 2020 |
| Alpha Compliance Training Limited | Education | 2020 |
| Alpha Silanus Ltd | Hospitality | 2023 |
| Alpha Sport Racing Ltd | Arts & recreation | 2023 |
| Alpha Swanson Ltd | Professional & scientific | 2013 |
| Alpha-Ref Limited | Construction | 2020 |
| Alphabet Artists Ltd | Education | 2016 |
| Alphawaterhygiene Ltd | Education | 2020 |
| Alptraum Limited | Information & communication | 2013 |
| Alpwell Ltd | Hospitality | 2001 |
| ALS Bubble Tea York Ltd | Hospitality | 2026 |
| Alsafir Property Limited | Real estate | 2025 |
| Alsj & Co Limited | Health & social care | 2023 |
| ALT Construction York Ltd | Construction | 2025 |
| ALT Plumbing Ltd | Construction | 2025 |
| Alta Zenith Fitness Ltd | Arts & recreation | 2025 |
| Alta Zenith Limited | Professional & scientific | 2021 |
| Altcon Ltd | Construction | 2017 |
| Altera Search Limited | Administrative & support | 2026 |
| Alteration Holdings Ltd | Real estate | 2020 |
| Alterations Express Limited | Other services | 2016 |
| Alterbridge Investments Limited | Real estate | 2022 |
| Alternate Waste Limited | Administrative & support | 2025 |
| Altherm Ltd | Energy | 2019 |
| Altius IFA Limited | Financial services | 2025 |
| Altius Two IFA Limited | Financial services | 2026 |
| Alto Roofline Ltd | Construction | 2025 |
| Altola Property Renovation Limited | Construction | 2019 |
| Altor Fire Limited | Professional & scientific | 2013 |
| Aluglas Projects Limited | Construction | 2000 |
| Alurain UK Ltd | Manufacturing | 2021 |
| Alvix Prime Ltd | Wholesale & retail | 2026 |
| Always Open Golf Limited | Arts & recreation | 2026 |
| ALX Exceptional Vehicles Limited | Financial services | 2023 |
| ALX1 Limited | Wholesale & retail | 2013 |
| Alys Cheesecake Ltd | Hospitality | 2021 |