| Black Garlic (UK) Limited | London | 2010 |
| Black Gold Jewelry Ltd | London | 2026 |
| Black Gold Productions Limited | Cardiff | 2020 |
| Black Group Scotland Limited | Livingston | 2026 |
| Black Habit Limited | Crawley | 2023 |
| Black Heart 74 Ltd | Rainham | 2023 |
| Black Heart Control & Automation Ltd | Sheffield | 2024 |
| Black Heart Soap Ltd | Aberdeen | 2025 |
| Black Hill Conversions Ltd | Holmfirth | 2025 |
| Black Hills Products Limited | Gosforth | 2017 |
| Black History Salute Limited | London | 2025 |
| Black Hole Brewery Limited | Derby | 2014 |
| Black Holt Wood Ltd | Grimsby | 2022 |
| Black Horse Joinery Ltd | Swindon | 2026 |
| Black Horse Stables & Field Shelters Limited | Coleford | 2021 |
| Black Ice Bikinis Ltd | Ryehill | 2022 |
| Black Ice Design & Print Limited | London | 2005 |
| Black Insomnia Ltd | Winchester | 2018 |
| Black Iron Energy Ltd | Swansea | 2025 |
| Black IS Gold by MB Ltd | Southampton | 2024 |
| Black Isle Brewing Co. Ltd. | Ross Shire | 1998 |
| Black Isle Bronze Limited | Nairn | 2003 |
| Black Isle Services Ltd | Inverness | 2025 |
| Black Ivory Ltd | Bristol | 2020 |
| Black Knight Catering Ltd | Cleethorpes | 2014 |
| Black Knight Supplements Ltd | Witham | 2012 |
| Black Label Print Ltd | Blackpool | 2025 |
| Black Label Vehicle Wraps Ltd | Bangor | 2025 |
| Black Labs London Ltd | Croydon | 2020 |
| Black Lake Kitchens Limited | Wednesbury | 2014 |
| Black Leopard Jewellers Ltd | London | 2022 |
| Black Limpet Ltd | London | 2025 |
| Black Line Coffee Limited | Basildon | 2026 |
| Black Lion Press Limited | Maidstone | 1981 |
| Black Liquorice Company Limited | Evesham | 2015 |
| Black Lizard Oilfield Services Limited | Glasgow | 2012 |
| Black Lodge Furniture Ltd | Willenhall | 2025 |
| Black Lodge Potions Ltd | Willenhall | 2019 |
| Black Magic Metalworks Ltd | Kendal | 2023 |
| Black Market Limited | Glasgow | 2017 |
| Black Metal Brewery Ltd | Edinburgh | 2012 |
| Black Modern Media Productions Ltd | Newtownards | 2022 |
| Black Moon Distillery Ltd | Newhaven | 2020 |
| Black Moon Guitars Ltd | Ilkley | 2014 |
| Black Moon Lighting Ltd. | Loanhead | 2004 |
| Black Moose Cycles Ltd | Atherstone | 2019 |
| Black Mountain Distillery Ltd | Llandeilo | 2022 |
| Black Mountain Gates Ltd | Abergavenny | 2022 |
| Black Mountain Shepherds Huts Limited | Welshpool | 2011 |
| Black Mountains Roast Ltd | Hereford | 2021 |
| Black Mountains Smokery Limited | Usk | 1995 |
| Black Night Orangery Ltd | Leeds | 2019 |
| Black Oak Farm Limited | York | 2026 |
| Black Oak Solutions Ltd | Bridgwater | 2022 |
| Black of Dunoon (Bakers) Limited | Argyll | 1978 |
| Black Opal the Fitted Furniture Company Limited | Wickford | 2020 |
| Black Opall Ltd | Barking | 2024 |
| Black OPS Baits Ltd | Peterborough | 2025 |
| Black OPS Nutrition Ltd | Bradford | 2025 |
| Black Owned London Ltd | Barnet | 2020 |
| Black Owned Swim School CIC | London | 2022 |
| Black Panta Ltd | London | 2023 |
| Black Pear Bespoke Ltd | Worcester | 2023 |
| Black Pear Ltd | Kingswinford | 2019 |
| Black Pear Weaving Limited | Bromsgrove | 2025 |
| Black Pearl Dental Laboratory Ltd | South Croydon | 2023 |
| Black Phoenix Games Ltd | Pinner | 2016 |
| Black Pine Iron Craft Studio Ltd | Enniskillen | 2026 |
| Black Powder GIN Company Ltd | Preston | 2016 |
| Black Print Wondering Ltd | Rowley Regis | 2022 |
| Black Rabbit Bakery Ltd | Leicester | 2024 |
| Black Rabbit Park Limited | West Midlands | 2023 |
| Black Racing Team Ltd | Lymington | 2013 |
| Black Rainbow Project Ltd | London | 2020 |
| Black Research Laboratories Ltd | Tunbridge Wells | 2026 |
| Black Rhino Engineering Ltd | Dungannon | 2026 |
| Black River Media Ltd | London | 2021 |
| Black Rock Marine Joinery Ltd. | Penryn | 2019 |
| Black Rock Model Rail Company Ltd | Hastings | 2019 |
| Black Rocks Distillery Limited | Belper | 2024 |
| Black Rooster Limited | Borehamwood | 2013 |
| Black Rose Photo & Video Production (Brpvp) CIC | Nottingham | 2025 |
| Black Scorpion Miniatures Ltd | Cullompton | 2021 |
| Black Scorpion Studios Ltd | London | 2025 |
| Black Shackle Rigging and Productions Limited | Billericay | 2015 |
| Black Sheep Coffee Bar Limited | London | 2020 |
| Black Sheep Coffee Beans Limited | London | 2020 |
| Black Sheep Coffee Cafes Limited | London | 2019 |
| Black Sheep Coffee Kiosks Limited | London | 2017 |
| Black Sheep Coffee Ltd | London | 2013 |
| Black Sheep Coffee Manchester Ltd | London | 2017 |
| Black Sheep Coffee Outlets Limited | London | 2020 |
| Black Sheep Coffee Retail Limited | London | 2020 |
| Black Sheep Coffee Shops Limited | London | 2017 |
| Black Sheep Coffee Stores Limited | London | 2020 |
| Black Sheep Coffee Trading Limited | London | 2020 |
| Black Sheep Composites Ltd | Cambridge | 2025 |
| Black Sheep Ironworks Limited | Carnforth | 2002 |
| Black Sheep Limited | Norwich | 1982 |
| Black Sheep Norfolk Limited | Wymondham | 2025 |