| Länsmansbärby Entreprenad AB | Örsundsbro | 0 tkr |
| Lars Lundbergs Förvaltning AB | Örsundsbro | 0 tkr |
| Ledarskap i Mälardalen AB | Ekolsund | 0 tkr |
| LexLie AB | Enköping | 0 tkr |
| LG Ståhl Bolagen AB | Enköping | 0 tkr |
| Libitum AB | Enköping | 0 tkr |
| Lidén Invest AB | Enköping | 0 tkr |
| Lidingby Invest AB | Enköping | 0 tkr |
| Lifco AB (publ) | Enköping | 0 tkr |
| Linda Persson New Location AB | Enköping | 0 tkr |
| Lindborgs Kastanjehus AB | Örsundsbro | 0 tkr |
| Lindevalls Invest AB | Enköping | 0 tkr |
| Linehal AB | Enköping | 0 tkr |
| Linlou AB | Enköping | 0 tkr |
| Liquid Eight Games AB | Fjärdhundra | 0 tkr |
| Little Meadow AB | Bålsta | 0 tkr |
| LL Capital AB | Enköping | 0 tkr |
| Lötsberga AB | Grillby | 0 tkr |
| Lp4 Invest AB | Ekolsund | 0 tkr |
| LP Power Ranch AB | Enköping | 0 tkr |
| Lycon Engineering Aktiebolag | Enköping | 0 tkr |
| LYDH Holding AB | Enköping | 0 tkr |
| Magnus Alm Utveckling AB | Enköping | 0 tkr |
| Magnus Lind Gåsbacken AB | Enköping | 0 tkr |
| Magnus Lind i mälardalen AB | Enköping | 0 tkr |
| Magnus Sjöholm AB | Enköping | 0 tkr |
| MA IT-Consulting AB | Enköping | 0 tkr |
| MA Konsult & Försäljning AB | Falun | 0 tkr |
| Makriax Holding AB | Grillby | 0 tkr |
| Mälardalens Care AB | Enköping | 0 tkr |
| Mälardalens tak & solteknik AB | Enköping | 0 tkr |
| Mälardalsparti Aktiebolag | Enköping | 0 tkr |
| Mälarlaser Fastighet AB | Enköping | 0 tkr |
| Måleri & Ytskikt Mälardalen AB | Västerås | 0 tkr |
| Maruf invest A AB | Enköping | 0 tkr |
| Mästervarg invest AB | Enköping | 0 tkr |
| Mats Englundh Invest AB | Enköping | 0 tkr |
| Mats Loberg Konsult & Förvaltning AB | Enköping | 0 tkr |
| Mats Marklund konsult AB | Örsundsbro | 0 tkr |
| Mats Wahlén Elkraftkonsult AB | Enköping | 0 tkr |
| Maxwell Coaching & Consulting AB | Vaxholm | 0 tkr |
| Medili AB | Örsundsbro | 0 tkr |
| Metlab Fastigheter Holding AB | Enköping | 0 tkr |
| MFD Capital AB | Enköping | 0 tkr |
| MGNT Consulting AB | Ekolsund | 0 tkr |
| MH VVS Konsult AB | Enköping | 0 tkr |
| Mix Kompetens AB | Enköping | 0 tkr |
| MJ Network Services i Mälardalen AB | Fjärdhundra | 0 tkr |
| MME Förvaltning AB | Enköping | 0 tkr |
| M&M Görl AB | Enköping | 0 tkr |