| Ma Foi Academy 1800446800 |
| Maersk India 1800225556 |
| Magicbricks 18002004050 |
| Maharishi Dayanand Univ Rohtak 18601801810 |
| Mahindra 1800226075 18002096006 |
| Mahindra 2 Wheelers 18002338883 |
| Mahindra First Choice 18001024800 |
| Mahindra Kisan Mitra/Tractors 18004256576 |
| Mahindra Powertrac 18001032010 |
| Mahindra Renault 1800226006 |
| MakeMyTrip.Com 1800118687 18001028687 1800118747 18001028747 18605005000 18001028900 18001032100 |
| Manav Rachna International University (MRIU) 18001020707 |
| Mangalaytan University 18001028686 |
| Manipal University 18004256243 |
| Mankind Pharma 18001034400 |
| Manmar Technologies 1800334420 |
| Manupatra 18001803550 |
| Manya Education 18001024646 |
| Manyavar Fashions 180030700500 |
| Marathon Electric 18004191500 |
| Marriott 1800220044 |
| Marshal's Point – 1800334488 |
| Maruti – 1800111515 |
| Maruti Eeco–18001800180 9910202020 |
| Massey Ferguson Tractors 18004259797 |
| Matrix 1800111500 |
| Max Bupa 180030103333 |
| Max New York Life 18001805577, 18002005577 1800335577 18004200435 |
| Max Vijay 18004194194 |
| Maxx 1800226299 |
| MBD Alchemie 18002002233 |
| MDIndia Healthcare Services 18002331166 |
| MDLR Airlines 18001031800 |
| Med Save Health Care Third Party Administrator (TPA) 1800111142 |
| Medical University of South Carolina (MUSC) USA 18001030006 |
| Medicare TPA Services Third Party Administrator (TPA) 1800333339 |
| Medybiz 18002000999 |
| Meena Bazaar 18001022696 Lucknow |
| MercedesBenz 18001029222 |
| MercedesBenz Zigwheels 18002123374 |
| Metlife 18004256969 |
| Metro Cash & Carry 18004250099 |
| Micro Technologies 18002092000 |
| Micromax 18605008286 |
| Microsoft 1800111100, 18001021100 |
| Microsoft Store 1800114001 |
| Microsoft Virus Update – 1901 333 334 |
| Mid Day Meal U.P. 18004190102 |
| Milton Homeware 18002092151 |
| Ministry of Health and Family Welfare (MOHFW) 1800114377 1800110456 |
| Ministry of Overseas Indian Affairs (MOIA) 1800113090 |
| Mirae Asset Mutual Fund 18001020777 |
| MIT School of Distance Education (MITSDE) 18002336376 |
| Mitzvah Engg. Inc 18001801120 |
| MMS Forex 18001801245 |
| MMTC Retail 18001800000 |
| MMTP Gold Medallion 18001800000 |
| Modi Academic International Institute (MAII) 1800119484 |
| Mom & Me 18001030606 |
| Monster.com 18004254032, 18004196666 |
| Monte Carlo/Canterbury/OWMNahar 18001800501 |
| Morgan Stanley Investments 18004251313 |
| Morning Walker 18003456999 |
| Morphy Richards 1800226722 |
| Moserbaer 1800111113 |
| Moserbaer Home Video 1800221099, 18001021099 |
| Mother Dairy 18001801018 |
| Motorola (MotoAssist) 180030004343, 1800111211 |
| Mrs Bector's Food Specialities 18001802254 (Sauce) / 18001802045 (Biscuit) |
| Msankalp 18001022272 |
| MSC Ship Management India 18002092555 |
| MSME 18001806763 |
| MTech Developers 1800116363 |
| MTNL Mobile Service 1800115151 |
| MTNL Trustline 1800118855, 1800224411 |
| Mumbai Educational Trust (MET) 1800220234 |
| Municipal Corporation of Ghaziabad (MCG) 18001803012 |
| Muthoot Fincorp 18001021616 |
| mVaayoo Bulk SMS 18002666263 |
| MVL Limited 18001022288 |
| MVL Mobiles 18001025888 |
| MVN Education 18001039888 |
| MyPlayWin.com 1800229292, 1800229393 |
