| Luigi Lar Peckerman, S.L. | Valencia |
| Lyra Tech, S.L. | Madrid |
| M-3 Informatica, S.L. | Madrid |
| M. Hermida Informatica, S.A. | Madrid |
| M.A Software | Barcelona |
| M.SOFT Worldwide | Barcelona |
| Ma-No Web Design and Development, S.L. | Balearic Islands |
| Mabisat Levante | Valencia |
| mAbxience | León |
| Mac Line S.C. | Biscay |
| Mac-Rapid | Madrid |
| Macadia Diseño Web Coruña | A Coruña |
| Machinas | Barcelona |
| Made of Genes | Barcelona |
| Madinsa | Toledo |
| Madisa | Balearic Islands |
| Madrid Content City | Madrid |
| Madritonic, S.L. | Madrid |
| MADSystems | Barcelona |
| Magis Teams | Barcelona |
| Magistral Ventures, S.L. | Castellón |
| Magnolia Web | Albacete |
| MainMemory | Barcelona |
| MaisMedia | Lugo |
| MakeSoft Technologies | Madrid |
| Makespace Madrid | Madrid |
| MalagaMicro | Málaga |
| Mallando no Android | A Coruña |
| ManchaNet, S.L.L. | Ciudad Real |
| MandanWebs.com | Barcelona |
| Mansion Studios, S.L. | Balearic Islands |
| Mantedif | Madrid |
| Mantenimiento Informático | Madrid |
| Mantra Internet, S.L.N.E. | Madrid |
| MAP | Barcelona |
| Maquetas Tech | Madrid |
| Maquinas el Siete, S.A. | Madrid |
| Marfeel | Barcelona |
| Margen Multimedia, S.L. | Madrid |
| Marina Tel and Data, S.L. | Barcelona |
| Marketalia | Madrid |
| Marketeros Web | Madrid |
| marketgoo.com | Madrid |
| MarketiNet Agencia de Marketing Digital, S.L. | Madrid |
| marketingpublicidad | Sevilla |
| Marzo | Madrid |
| MAS2D | Málaga |
| MasBytes, S.L. | Navarre |
| MasQSoft Consultores, S.L. | Madrid |
| Mastac, S.L. | Barcelona |