| Mazhar and Sons Ltd | Construction | 2021 |
| Mazhar Meat Shop Ltd | Other services | 2018 |
| Mazhar Medical Ltd | Health & social care | 2014 |
| Mazowsze Ltd | Wholesale & retail | 2017 |
| Mazpak Ltd | Hospitality | 2023 |
| Mazshah Limited | Administrative & support | 2015 |
| Mazuli Ltd | Construction | 2020 |
| MB 1NTERIORS Ltd | Manufacturing | 2013 |
| MB Booze Ltd | Wholesale & retail | 2026 |
| MB Care Ltd | Administrative & support | 2025 |
| MB Event Solutions Limited | Education | 2017 |
| MB Foods BFD Limited | Hospitality | 2024 |
| MB Heaven Limited | Administrative & support | 2019 |
| MB Motorhouse Ltd | Wholesale & retail | 2025 |
| MB Photography Services Limited | Professional & scientific | 2022 |
| MB SAM Couriers Ltd | Transport & logistics | 2026 |
| MB Smart Services Ltd | Information & communication | 2025 |
| MB Transformation Services Limited | Professional & scientific | 2013 |
| Mb-Es Electrical Contractors Ltd | Manufacturing | 2012 |
| Mb.Prod Ltd | Information & communication | 2026 |
| Mbbd Ltd | Construction | 2024 |
| MBC Bradford Ltd | Professional & scientific | 2024 |
| Mbdh AI Ltd | Information & communication | 2026 |
| Mbey Services Ltd | Administrative & support | 2025 |
| MBG Asset Holdings Limited | Arts & recreation | 2022 |
| Mbhp Pipework Services Ltd | Administrative & support | 2023 |
| MBI Services Limited | Administrative & support | 2009 |
| MBK BD Limited | Real estate | 2019 |
| MBK Performance Ltd | Wholesale & retail | 2020 |
| MC 1 Autos Ltd | Wholesale & retail | 2025 |
| MC Developments Lancashire Ltd | Construction | 2020 |
| MC Drinks Consultancy Limited | Wholesale & retail | 2021 |
| MC Elevana Limited | Wholesale & retail | 2025 |
| MC Heritage Consulting Limited | Information & communication | 2023 |
| MC Kennel Supplies Ltd | Manufacturing | 2019 |
| MC Logistics Limited | Transport & logistics | 1999 |
| MC Road Runners Ltd | Transport & logistics | 2019 |
| MC3 Investments Ltd | Real estate | 2026 |
| MCB Electrical Contractors Ltd | Construction | 2022 |
| MCC Auto Repair Centre Limited | Wholesale & retail | 2021 |
| MCC Building Solutions Limited | Real estate | 2023 |
| Mccaig Contract Cleaning Services Limited | Administrative & support | 2023 |
| Mccormack Trading Ltd | Arts & recreation | 2025 |
| Mccoy Estates Management Ltd | Real estate | 2010 |
| Mccrea Yorkshire Limited | Real estate | 2021 |
| Mccullagh Ramsay Management Limited | Arts & recreation | 2026 |
| MCD Auctions Limited | Extraterritorial | 2023 |
| MCD Security Systems Ltd | Administrative & support | 2015 |
| Mcdaid Electrical Contractors Limited | Construction | 2024 |
| Mcdonnell Plumbing Heating & Electrical Limited | Construction | 2005 |
| MCE Bess Ltd | Construction | 2025 |
| MCE Electrical Contractors Ltd | Construction | 2015 |
| Mcfaddens Car Sales Limited | Wholesale & retail | 2015 |
| Mchale Contracts and Plant Environmental LLP | | 2009 |
| Mchale Mechanical Services Ltd | Construction | 2021 |
| Mcjeffers Consults Limited | Professional & scientific | 2015 |
| MCK Assets Limited | Financial services | 2024 |
| MCK Healthcare Limited | Health & social care | 2026 |
| Mckenna Group Limited | Professional & scientific | 2015 |
| Mckesta Ltd | Professional & scientific | 2020 |
| MCL Group Investments Ltd | Real estate | 2025 |
| Mclean & Family Limited | Wholesale & retail | 2024 |
| Mcleod Tower Crane Services Ltd | Construction | 2025 |
| Mcmanus Group Holdings Limited | Professional & scientific | 2015 |
| Mcnt Ltd | Wholesale & retail | 2021 |
| Mcooney Ltd | Hospitality | 2023 |
| MCP Balloon Newcastle Limited | Construction | 2024 |
| MCP Birmingham TR Ltd | Construction | 2024 |
| MCP Blackpool George Street Ltd | Construction | 2025 |
| MCP Cannock Ltd | Construction | 2025 |
| MCP Congleton Ltd | Construction | 2024 |
| MCP Doncaster WHR Ltd | Construction | 2025 |
| MCP Dudley Ltd | Construction | 2025 |
| MCP Environmental Group Limited | Financial services | 2015 |
| MCP Environmental Holdings Limited | Financial services | 2015 |
| MCP Environmental Limited | Administrative & support | 2015 |
| MCP Environmental Services Limited | Financial services | 2015 |
| MCP Gosforth Newcastle Ltd | Construction | 2025 |
| MCP Lincoln Tentercroft Ltd | Construction | 2025 |
| MCP Northampton Ltd | Construction | 2025 |
| MCP Peterborough Ltd | Construction | 2025 |
| MCP RCF1 Ltd | Construction | 2025 |
| MCP Rochdale OR Ltd | Construction | 2025 |
| MCP Rossington Ltd | Construction | 2024 |
| MCP Rotherham Ltd | Construction | 2025 |
| MCP Starbucks Birmingham WR Ltd | Construction | 2024 |
| MCP Starbucks Bradford Ltd | Construction | 2024 |
| MCP Starbucks Guisborough Ltd | Construction | 2024 |
| MCP Starbucks Mansfield Limited | Construction | 2024 |
| MCP Starbucks Skelmersdale Ltd | Construction | 2024 |
| MCP Starbucks Stoke JBW Ltd | Construction | 2024 |
| MCP Starbucks Stoke Longton Ltd | Construction | 2024 |
| MCP Starbucks Stoke Tunstall Ltd | Construction | 2024 |
| MCP Stoke DB Ltd | Construction | 2025 |
| MCP Sunderland Ltd | Construction | 2024 |
| MCP Varley House Ltd | Construction | 2026 |
| Mcpeake & SON Ltd | Transport & logistics | 2024 |
| MCR Car Leasing Ltd | Administrative & support | 2025 |
| MCR Central Ltd | Real estate | 2025 |
| MCS Cleaning Services Yorkshire Ltd | Administrative & support | 2024 |