| Malmsjö Byggservice AB | Vagnhärad | 0 tkr |
| Malou Entreprenad AB | Mariefred | 0 tkr |
| Mälsåker vingård AB | Stallarholmen | 0 tkr |
| Mama tried holding AB | Strängnäs | 0 tkr |
| Mamba Holding AB | Stora Sundby | 0 tkr |
| Mandeville Holding AB | Eskilstuna | 0 tkr |
| M. Andrén Holding AB | Eskilstuna | 0 tkr |
| Manfri AB | Nyköping | 0 tkr |
| Mangior AB | Vingåker | 0 tkr |
| Mannering Holding AB | Vagnhärad | 0 tkr |
| Måns Eriksson Holding AB | Tystberga | 0 tkr |
| Manuela Milevoj AB | Eskilstuna | 0 tkr |
| Mapimi Förvaltning AB | Nyköping | 0 tkr |
| Marcus Annebäck AB | Nyköping | 0 tkr |
| Marcus Karlsson Invest AB | Eskilstuna | 0 tkr |
| Marcus Lindmark AB | Torshälla | 0 tkr |
| Marcus Westöö AB | Katrineholm | 0 tkr |
| Mårdh Konsult AB | Eskilstuna | 0 tkr |
| Mårds Holding AB | Eskilstuna | 0 tkr |
| MariaKliniken Holding AB | Strängnäs | 0 tkr |
| Maria Kruhsberg Byggnadsingenjör AB | Västra Näshulta | 0 tkr |
| Marianne Bengt Globalt Aktiebolag | Strängnäs | 0 tkr |
| Marianne kliniken i Eskilstuna AB | Nyköping | 0 tkr |
| Maria Öström Holding AB | Torshälla | 0 tkr |
| Mariba Holding AB | Eskilstuna | 0 tkr |
| Mariedamm Solar AB | Näshulta | 0 tkr |
| Mariefreds Entreprenad AB | Mariefred | 0 tkr |
| Mariefreds Pizza House Aktiebolaget | Mariefred | 0 tkr |
| Mariefreds Teknikkonsult AB | Mariefred | 0 tkr |
| Mariéll Invest AB | Vagnhärad | 0 tkr |
| MARINDATA MÄLARBADEN Aktiebolag | Torshälla | 0 tkr |
| Markbolaget Kruus AB | Mariefred | 0 tkr |
| Market Import Sweden Aktiebolag | Nyköping | 0 tkr |
| Marketing by TWC AB | Älvsjö | 0 tkr |
| Markne Holding AB | Mariefred | 0 tkr |
| Marmorbyns VVS Tjänst Aktiebolag | Katrineholm | 0 tkr |
| MAROAL AB | Torshälla | 0 tkr |
| Marrollar AB | Eskilstuna | 0 tkr |
| MarSim Holding AB | Torshälla | 0 tkr |
| Marsviksstrand AB | Nyköping | 0 tkr |
| Martell Invest AB | Eskilstuna | 0 tkr |
| Martin Atterby AB | Linköping | 0 tkr |
| Martin Consulting AB | Mariefred | 0 tkr |
| Martin Strand Holding AB | Näshulta | 0 tkr |
| Martti & Vuokko AB | Katrineholm | 0 tkr |
| Marvatten AB | Trosa | 0 tkr |
| Mary Marie Invest AB | Eskilstuna | 0 tkr |
| MarZill AB | Björnlunda | 0 tkr |
| MASEN & ERIKSSON HOLDING AB | Nyköping | 0 tkr |
| Maskindesign Ingemar Lundin Aktiebolag | Tystberga | 0 tkr |