| KB Music Ltd | Information & communication | 2026 |
| Kbit Communications Ltd | Information & communication | 2011 |
| KBS Traders Ltd | Wholesale & retail | 2022 |
| Kchau Ltd | Real estate | 2017 |
| Kdev Solutions Limited | Wholesale & retail | 2020 |
| Keaney Brothers U.K Limited | Construction | 2023 |
| Kelly J Taggart Consulting Services Ltd | Professional & scientific | 2024 |
| Kenot Estates Ltd | Real estate | 2025 |
| Keswick House Ltd | Households | 2013 |
| Key Building Works Ltd | Construction | 2006 |
| Key Shareholder Ltd | Real estate | 2021 |
| Keyal Ltd | Wholesale & retail | 2025 |
| Keystone Properties Development Limited | Real estate | 2025 |
| Khabra Properties Ltd | Real estate | 2015 |
| Khalsa Surveying Ltd | Real estate | 2021 |
| Khamsin Global IM Ltd | Professional & scientific | 2023 |
| Khan Accountancy Limited | Administrative & support | 2012 |
| Khandy Development Ltd | Construction | 2015 |
| Khir Kommerce Limited | Wholesale & retail | 2020 |
| Khizer Smile Limited | Health & social care | 2020 |
| Khurum Khan's Limited | Health & social care | 2021 |
| Kick Engineers Limited | Professional & scientific | 2026 |
| Kilnaleck Construction Limited | Construction | 2016 |
| Kimiki Solutions Ltd | Information & communication | 2016 |
| Kimiti Ltd | Real estate | 2017 |
| Kind Juice Limited | Hospitality | 2019 |
| King's Way Culture Exchange Ltd | Transport & logistics | 2013 |
| Kings Industry Limited | Construction | 2022 |
| Kingsley Meat Market Limited | Wholesale & retail | 2013 |
| Kingsmere Leather Ltd | Manufacturing | 2025 |
| Kirat Singh Real Estate 2 Ltd | Real estate | 2023 |
| Kirat Singh Real Estate Ltd | Real estate | 2020 |
| Kiritara Limited | Other services | 2025 |
| Kitchen Culture Design Ltd | Wholesale & retail | 2020 |
| Kiwi Consulting Ltd | Information & communication | 2026 |
| Kiwi Group Holdings Ltd | Information & communication | 2026 |
| KJS Solutions Limited | Administrative & support | 2020 |
| KKP & Co Limited | Professional & scientific | 2014 |
| Klasyczna Polonia Limited | Information & communication | 2007 |
| KLC Group Ltd | Professional & scientific | 2018 |
| Kmet Limited | Professional & scientific | 2016 |
| Kneadin Ltd Limited | Hospitality | 2024 |
| Knees for Life Ltd | Professional & scientific | 2012 |
| Kneller Hair Limited | Other services | 2015 |
| Kodonim Ltd | Real estate | 2022 |
| Kohinoor of London Limited | Wholesale & retail | 2004 |
| Kojok Properties Ltd | Real estate | 2022 |
| Konsylium Investments Ltd | Real estate | 2018 |
| Konsylium Limited | Health & social care | 2010 |
| Koolminds Limited | Information & communication | 2014 |
| Kore Systems Limited | Administrative & support | 2002 |
| Korean Tech Construction Limited | Construction | 2021 |
| Kosary Group Ltd | Real estate | 2022 |
| Kosary Investments Limited | Real estate | 2024 |
| Kpmj Solutions Ltd | Hospitality | 2026 |
| KPS Security Ltd | Administrative & support | 2009 |
| Kris HGV Transport Ltd | Transport & logistics | 2016 |
| Krishna Kanhaiya Limited | Hospitality | 2015 |
| Krishna Solutions Ltd | Professional & scientific | 2012 |
| Krti Ltd | Information & communication | 2012 |
| Krystal Beauty Clinic Ltd | Other services | 2019 |
| Ksavi Ltd | Other services | 2014 |
| KSP Dreams Homes Limited | Real estate | 2023 |
| KSP Heating & Plumbing Limited | Wholesale & retail | 2023 |
| Ksrs Ltd | Real estate | 2021 |
| KST London Limited | Wholesale & retail | 2011 |
| KTR1 Ltd | Construction | 2025 |
| KTZ Communications Limited | Professional & scientific | 2010 |
| Kumar Smiles Limited | Health & social care | 2016 |
| Kupa Construction Ltd | Construction | 2021 |
| KV (U.K.) Investment Limited | Financial services | 2016 |
| KW Home Services Ltd | Wholesale & retail | 2024 |
| KXT Group Ltd | Wholesale & retail | 2020 |
| Kyasus Limited | Professional & scientific | 2022 |
| Kyralex Limited | Real estate | 2018 |
| L&A Contractors Ltd | Construction | 2022 |
| L&A Smartbuild Solutions Ltd | Construction | 2024 |
| L&A Sons Recycling Ltd | Water & waste | 2025 |
| L'Adore Limited | Wholesale & retail | 2010 |
| L'Amore Coffee and More Ltd | Wholesale & retail | 2023 |
| L.Doherty Ltd | Professional & scientific | 2019 |
| L.O.X Limited | Arts & recreation | 2011 |
| L@Vm Limited | Wholesale & retail | 2024 |
| LA Raqueta Ltd | Extraterritorial | 2023 |
| LA Reserve Northern Limited | Construction | 2024 |
| LAB Retail Ltd | Wholesale & retail | 2025 |
| Labaik Instruments Limited | Real estate | 2019 |
| Lagercrantz UK Limited | Financial services | 2001 |
| Lahori West Hair Ltd | Other services | 2023 |
| Lakam Properties Limited | Real estate | 2019 |
| Lala NU Property Investments Ltd | Real estate | 2025 |
| Lalej Services Limited | Administrative & support | 2025 |
| Lamb Urology Consultants Limited | Other services | 2019 |
| Lambda Tech Limited | Information & communication | 2025 |
| Landen Limited | Extraterritorial | 2018 |
| Landmark Building Services Ltd | Construction | 2015 |
| Landmark Investment Properties Limited | Real estate | 2021 |
| Langley Skip Hire Limited | Water & waste | 2007 |
| Language Source Limited | Information & communication | 1999 |
| Larpent Developments Limited | Real estate | 2022 |