| Adam's Barber Peterborough Limited | Other services | 2024 |
| Adams & Brothers Limited | Wholesale & retail | 2022 |
| Adams Fresh Fruit and VEG Limited | Wholesale & retail | 2023 |
| Adams Plant Inspections Ltd | Professional & scientific | 2015 |
| Adams Pride Ltd | Wholesale & retail | 2010 |
| Adams Self Drive Limited | Administrative & support | 2000 |
| Adams Taxis 1958 Ltd | Transport & logistics | 2026 |
| Adaobi Fertility CIC | Education | 2024 |
| Adaptive Procurement Solutions Limited | Professional & scientific | 2015 |
| ADC Haulage Ltd | Transport & logistics | 2026 |
| ADC Supplies Ltd | Wholesale & retail | 2026 |
| Adcocks Property Company Limited | Real estate | 2020 |
| ADD Kado Limited | Wholesale & retail | 2025 |
| Addaj Properties Limited | Real estate | 2020 |
| Addenda Synergy Ltd | Wholesale & retail | 2022 |
| Addington Road Care Limited | Extraterritorial | 2025 |
| Adedoyin Adebisi Limited | Wholesale & retail | 2025 |
| Adenie Ltd | Other services | 2017 |
| Adept Brickwork Ltd | Construction | 2022 |
| Adept Flooring Installations Limited | Construction | 2008 |
| Adexz Limited | Wholesale & retail | 2018 |
| Adey Drive Ltd | Transport & logistics | 2020 |
| Adhd Assessor Limited | Wholesale & retail | 2026 |
| Adheela.Ghouss Ltd | Health & social care | 2024 |
| Adho Holdings Limited | Real estate | 2019 |
| Adija Healthcare Ltd | Health & social care | 2026 |
| Adima Holdings Limited | Financial services | 2023 |
| Adinicol Ltd | Transport & logistics | 2022 |
| Adlerflug Ltd | Transport & logistics | 2024 |
| Adliv Host Limited | Households | 2020 |
| Adliv Limited | Real estate | 2018 |
| Admin Ace Limited | Administrative & support | 2021 |
| Admr Mihai Limited | Transport & logistics | 2025 |
| Adnob-Roses Ltd Ltd | Other services | 2018 |
| Adnova Distribution Ltd | Transport & logistics | 2025 |
| Adnova Marketing Ltd | Professional & scientific | 2023 |
| ADO Coffee Ltd | Wholesale & retail | 2025 |
| Adora & Miran Ltd | Hospitality | 2026 |
| Adore Digital Media Limited | Professional & scientific | 2015 |
| ADP Homecare Property Maintenance Ltd | Administrative & support | 2025 |
| ADR Dimond Wheels Ltd | Manufacturing | 2025 |
| ADR Dream Homes Limited | Real estate | 2022 |
| ADR Ionut Transport Limited | Transport & logistics | 2025 |
| Adri Services Ltd | Transport & logistics | 2020 |
| Adrian Drzazga Ltd | Transport & logistics | 2019 |
| Adrian Hotu Trans Ltd | Transport & logistics | 2025 |
| Adrian Johnston Limited | Arts & recreation | 1999 |
| Adrian Vasile Transport Ltd | Transport & logistics | 2022 |
| Adriano Cars Ltd | Wholesale & retail | 2020 |
| Adrika Trading Ltd | Information & communication | 2023 |
| Adsall Ltd | Wholesale & retail | 2024 |
| Aduaye Limited | Administrative & support | 2025 |
| Advance Driving Instructor Ltd | Education | 2021 |
| Advance Marketer Ltd | Administrative & support | 2017 |
| Advanced Biofuels Limited | Professional & scientific | 2017 |
| Advanced Climate Specialists Ltd | Construction | 2020 |
| Advanced Diesel Services Ltd | Wholesale & retail | 2021 |
| Advanced Fabrics Limited | Wholesale & retail | 2022 |
| Advanced Heating and Cooling Limited | Construction | 2003 |
| Advanced Investments Limited | Information & communication | 1997 |
| Advanced Mortgages Ltd | Financial services | 2019 |
| Advanced Payroll Services Limited | Administrative & support | 2001 |
| Advanevo Limited | Professional & scientific | 2019 |
| Advantage Agency Ltd | Professional & scientific | 2026 |
| Advantage Homes Peterborough Ltd | Real estate | 2025 |
| Advent Global Services Limited | Wholesale & retail | 2019 |
| Adventure Sports Tours Ltd | Hospitality | 2022 |
| Adventure Tribe Ltd | Education | 2020 |
| Advertise Care Limited | Professional & scientific | 2011 |
| Adviceunit Limited | Water & waste | 1995 |
| Adyy Barbers Limited | Other services | 2024 |
| Adùn RJ Ltd | Wholesale & retail | 2025 |
| AE Trans Ltd | Transport & logistics | 2023 |
| Aebi Schmidt UK Limited | Wholesale & retail | 1955 |
| AED Services Limited | Construction | 2026 |
| Aelix Services Ltd | Construction | 2016 |
| Aelred Consulting Limited | Professional & scientific | 2011 |
| Aero Fehu Ltd | Transport & logistics | 2026 |
| Aerobox Secure Containers Limited | Other services | 2014 |
| Aerographics GIS Limited | Professional & scientific | 2017 |
| Aeroline Consulting Limited | Professional & scientific | 2012 |
| Aeskin Ltd | Health & social care | 2026 |
| Aesthetic Skin Care Clinic Limited | Health & social care | 2025 |
| Aesthetics by Sofia Limited | Health & social care | 2019 |
| Aestheticsbylidia Ltd | Health & social care | 2024 |
| Aeternum Group Ltd | Professional & scientific | 2023 |
| Aethra Ltd | Information & communication | 2026 |
| Aex&Ade Transport Ltd | Transport & logistics | 2025 |
| AF & H Supermarket UK Limited | Wholesale & retail | 2018 |
| AF Restaurant (Stafford) Ltd | Hospitality | 2024 |
| AFB Consultants Limited | Wholesale & retail | 2018 |
| AFC Delivery Ltd | Transport & logistics | 2018 |
| Affectum Counselling Ltd | Health & social care | 2023 |
| Affiliated Property Investments Limited | Real estate | 2019 |
| Affinitas Global Ltd | Information & communication | 2015 |
| Affinity ALL Saints Limited | Administrative & support | 2012 |
| Affinity Distribution Limited | Wholesale & retail | 2006 |
| Affordable Carz Ltd | Wholesale & retail | 2023 |
| Affordable Fascias and Gutter Services Limited | Construction | 2019 |
| Affordable Fascias Limited | Construction | 2012 |