| Gainsborough Islamic & Cultural Centre Ltd | Education | 2024 |
| Gainsborough Kitchens Limited | Wholesale & retail | 2003 |
| Gainsborough Lounge Ltd | Hospitality | 2025 |
| Gainsborough Masonic Temple Limited | Hospitality | 1952 |
| Gainsborough Metals Ltd | Wholesale & retail | 2020 |
| Gainsborough MOT & Service Centre Limited | Wholesale & retail | 2006 |
| Gainsborough Motaquip Limited | Wholesale & retail | 2005 |
| Gainsborough Park Limited | Manufacturing | 2003 |
| Gainsborough Property Services Ltd | Real estate | 2014 |
| Gainsborough Scaffolding Ltd | Construction | 2022 |
| Gainsborough Scaffolding Services Limited | Construction | 2016 |
| Gainsborough Skip & Aggregates Ltd | Water & waste | 2025 |
| Gainsborough Trinity CIC | Arts & recreation | 2025 |
| Gainsborough Uphills Muga Group Limited | Construction | 2016 |
| Gainsborough Will Company Ltd | Other services | 2020 |
| Galcon Ltd | Professional & scientific | 2025 |
| Galtres Energy Limited | Energy | 2018 |
| Garage of Old Limited | Wholesale & retail | 2023 |
| Garden Angels (Scunthorpe) Limited | Administrative & support | 2007 |
| Gateway Fibre Solutions Ltd | Professional & scientific | 2011 |
| Gbpo Solutions Ltd | Professional & scientific | 2024 |
| GBS Barbers Ltd | Other services | 2025 |
| Geka Engineering Ltd | Construction | 2013 |
| GEO Resources Consultancy International UK Limited | Professional & scientific | 2020 |
| George's Hand Car Wash Ltd | Administrative & support | 2026 |
| George-Maya Investments Ltd | Wholesale & retail | 2020 |
| Geropa Ltd | Professional & scientific | 2023 |
| GET OFF the Tools Ltd | Professional & scientific | 2026 |
| Getta Gripp Ltd | Wholesale & retail | 2025 |
| Gilgal Limited | Health & social care | 2022 |
| Gillian Jackson Beauty Limited | Other services | 2016 |
| Girton Sailing Club Limited | Other services | 2013 |
| Giwanson Support Services Ltd | Other services | 2020 |
| GK & JNR Ltd | Transport & logistics | 2025 |
| Glamor Properties Ltd | Real estate | 2024 |
| Glenbury Limited | Wholesale & retail | 1997 |
| Glow With LIV EG Ltd | Other services | 2025 |
| GME Agricultural Contracting Ltd | Construction | 2012 |
| GME Electrical Ltd | Construction | 2017 |
| Gnosis Research Limited | Other services | 2022 |
| Goat Fulfilment Ltd | Wholesale & retail | 2025 |
| Gold Trade Ltd | Wholesale & retail | 2013 |
| Good Apple Independent School Ltd | Education | 2018 |
| Goodlad Investments Limited | Real estate | 2023 |
| Gordon K a Lochrie Limited | Professional & scientific | 2001 |
| Gotchar Limited | Information & communication | 2024 |
| Gough Surgical Services Limited | Health & social care | 2012 |
| GQA Online Ltd | Professional & scientific | 2022 |
| Grayrose Property Services Ltd | Real estate | 2025 |
| Greater Lincolnshire College Ltd | Education | 2025 |
| Green Beach Silver Moon Ltd | Professional & scientific | 2015 |
| Green Frame Windows Ltd | Other services | 2020 |
| Green Oases Ltd | Administrative & support | 2017 |
| Gregory & Robinson (Day Trips & Holidays) Ltd | Transport & logistics | 2020 |
| Gregory Coaches Ltd | Administrative & support | 2016 |
| Grigo Aviation Limited | Manufacturing | 1995 |
| Griss UK Limited | Professional & scientific | 2015 |
| GRL Consultancy and Trading Ltd | Construction | 2020 |
| Ground and Environmental Investigation Ltd | Professional & scientific | 2016 |
| GSP Kitchens & Joinery Ltd | Construction | 2025 |
| GSS Electrical Contractors Limited | Construction | 2025 |
| GT Smart Repair Ltd | Wholesale & retail | 2025 |
| GTC Property Services Ltd | Construction | 2025 |
| Guardstore Ltd | Transport & logistics | 2025 |
| Guild Marketing Limited | Professional & scientific | 2021 |
| Gulf Tides Ltd | Hospitality | 2026 |
| Gunnford Investments Limited | Real estate | 2020 |
| GVO B-1 Limited | Financial services | 2017 |
| GWW Trailers Ltd | Administrative & support | 2026 |
| H & S Installations Projects Limited | Construction | 2021 |
| H&K Retailers Limited | Wholesale & retail | 2025 |
| H&S Installations and Repair Services Limited | Construction | 2020 |
| H&W Enterprises Ltd | Hospitality | 2024 |
| H. Lockwood & SON Limited | Construction | 2006 |
| H.E. Smith (Scotter) Limited | Real estate | 1992 |
| H.Jefferson(Gringley)Limited | Agriculture & fishing | 1958 |
| Hackberry (Scotter) Ltd | Education | 2019 |
| Hades Solutions Limited | Water & waste | 2012 |
| HALDO616 Ltd | Professional & scientific | 2017 |
| Hallmark Family Homes Limited | Real estate | 2014 |
| Hampsons Property UK Ltd | Real estate | 2016 |
| Hamstone Pond Talbot Ltd | Administrative & support | 2016 |
| Hamzababa Limited | Hospitality | 2025 |
| Hanchu Technology Ltd | Information & communication | 2025 |
| Handel House (Gainsborough) Ltd | Education | 2017 |
| Handel House School Limited | Education | 2006 |
| Hanover Project Partners Ltd | Financial services | 2023 |
| Harbourland 1956 Limited | Extraterritorial | 2014 |
| Harlequin Studios Limited | Other services | 2022 |
| Harmless Cleaning&Removals Ltd | Transport & logistics | 2020 |
| Harmless Healthcare Ltd | Administrative & support | 2018 |
| Harpswell Farms Limited | Agriculture & fishing | 1977 |
| Harriet Developments Ltd | Construction | 2016 |
| Harrisonfamily Ltd | Wholesale & retail | 2025 |
| Hartrade Ltd | Wholesale & retail | 2022 |
| Hatfield & Co Accounting Services Limited | Professional & scientific | 2009 |
| Havana Garden Rooms Ltd | Construction | 2025 |
| Hawdale Limited | Hospitality | 2003 |
| HCM Contractors Limited | Administrative & support | 2019 |
| Head Inside Counselling Ltd | Other services | 2025 |