| Mettler Toledo Safeline X-ray Limited | Royston | Temporary Worker | A | View |
| Mews Systems Limited | London | Temporary Worker | A | View |
| MEXICHEM UK LIMITED (t/a Koura) | Cheshire | Temporary Worker | A | View |
| MH Foundation | Corby | Temporary Worker | A | View |
| MHA | Derby | Temporary Worker | A | View |
| Michael Grandage Company Ltd | London | Temporary Worker | A | View |
| Michael Harrison Entertainment | London | Temporary Worker | A | View |
| Michelin Tyre plc | Stoke-on-Trent | Temporary Worker | A | View |
| Mick Perrin Worldwide Holdings Ltd | Brighton | Temporary Worker | A | View |
| Mid Antrim Vineyard | Ballymena | Temporary Worker | A | View |
| Middle Ground Theatre Company Ltd | Malvern Wells | Temporary Worker | A | View |
| Middlesex University | London | Temporary Worker | A | View |
| Midnight Mango Ltd | Bridgwater | Temporary Worker | A | View |
| Mifadelo Global Religion Law and Health Found Ltd | London | Temporary Worker | A | View |
| Might & Grace Productions CIC | Milton Keynes | Temporary Worker | A | View |
| Migrant Centre NI | Lurgan | Temporary Worker | A | View |
| Migrants Organise | London | Temporary Worker | A | View |
| MILAP FESTIVAL TRUST | LIVERPOOL | Temporary Worker | A | View |
| Milk Management Limited | London | Temporary Worker | A | View |
| Millennium Circus Productions Ltd | Belfast | Temporary Worker | A | View |
| Millfield School | Street | Temporary Worker | A | View |
| Milton Keynes Murugan Temple Trust (CIO) | Milton Keynes | Temporary Worker | A | View |
| Mimbre Limited | London | Temporary Worker | A | View |
| Minamoto Kitchoan Europe Ltd | London | Temporary Worker | A | View |
| Minds I Media Ltd | London | Temporary Worker | A | View |
| Minhaj ul Quran International | London | Temporary Worker | A | View |
| MINHAJ-UL-QURAN WELFARE FOUNDATION | Manchester | Temporary Worker | A | View |
| Mini Title Ltd. | London | Temporary Worker | A | View |
| MINISTRIES WITHOUT BORDERS INTERNATIONAL | Cardiff | Temporary Worker | A | View |
| Ministry of Hope Ltd | London | Temporary Worker | A | View |
| Ministry of Reconciliation | Leicester | Temporary Worker | A | View |
| Ministry of Sound Group Ltd | London | Temporary Worker | A | View |
| Minoan Pictures Limited | Southam | Temporary Worker | A | View |
| MINORITY RIGHTS GROUP | London | Temporary Worker | A | View |
| Miracle Artists Ltd | Yelverton | Temporary Worker | A | View |
| Miracle Temple Assemblies of God Church | Milton Keynes | Temporary Worker | A | View |
| Mirai Power Europe Limited | London | Temporary Worker | A | View |
| MISS ENGLAND LIMITED | Leicester | Temporary Worker | A | View |
| Mission Foods Europe | Middlesex | Temporary Worker | A | View |
| Missionaries of Charity Brothers | Manchester | Temporary Worker | A | View |
| Missionaries of the Sacred Heart of Jesus | London | Temporary Worker | A | View |
| Missionary Congregation of Evangelizing Sisters of Mary | London | Temporary Worker | A | View |
| Missionary Sisters of the Immaculate | London | Temporary Worker | A | View |
| Missionary Society of St Paul | Brixton | Temporary Worker | A | View |
| Mitsubishi Corporation International (Europe) Plc | London | Temporary Worker | A | View |
| Mitsubishi HC Capital UK PLC | Staines upon Thames | Temporary Worker | A | View |
| MITUTOYO (UK) LTD | Andover | Temporary Worker | A | View |
| MJZ LTD | London | Temporary Worker | A | View |
| ML Film Holdings Ltd | London | Temporary Worker | A | View |
| MM Packaging Deeside Ltd | Deeside | Temporary Worker | A | View |
