| Magic Creative | Sofia |
| Mail.bg | Sofia |
| MAP marketing research | |
| MarchFirst | |
| Marins International Ltd | Sofia |
| Marmax Computers | Sofia |
| Mastermind Event | |
| Masterplan | Sofia |
| MAX Digital | |
| Maxcart | Sofia |
| MaxSoft | Sofia |
| MClimate | Sofia |
| MediaHub | |
| Medical University - Pleven | |
| Medical University of Plovdiv | Plovdiv |
| Megatex, Inc. | Sofia |
| MelioraWeb | |
| Melon AD | Sofia |
| Melon, Inc. | Sofia |
| Mental Modular Ltd | Sofia |
| Metasoft Ltd | Sofia |
| MetaVisia | Ruse |
| Methodia Web | |
| MGF Invest | |
| Micar21 | |
| Michail Grand Corporation Ltd | Sofia |
| Microaccount Ltd | Varna |
| MicroDicom | Sofia |
| Microsoft Bulgaria | Sofia |
| Microweber Academy | Sofia |
| Mikrosistemi Ltd | Varna |
| Mil Incorporated | Varna |
| Milanda Design Studio | Sofia |
| Mimech.com | Sofia |
| Mimirium | Varna |
| MindFusion, LLC | Sofia |
| Mirela Ltd | Sofia |
| Mirsolutions | Sofia |
| Missia23 | |
| Mistral Software | Sofia |
| MK IT Ltd | |
| Mnemonica JSC | Sofia |
| Mobica | Sofia |
| Mobility.BG | Sofia |
| MobiSystems | Sofia |
| Moderna BG Ltd | |
| MondoGames | Sofia |
| Moodlight | Sofia |
| Morningside Hill Capital Management | |
| Mosk Solutions | Sofia |